By Brian Williams, Anchor and managing editor

On the first feed of the broadcast tonight, a promised candlelight vigil became a series of hyper-amplified speeches, 50 yards behind us while we were on live television. From the very first plans we made to do the broadcast live from a grassy hillside across from the Lorraine Motel, we were promised (by event organizers) in no uncertain terms that it would be quiet -- if anything, there were concerns expressed early on, that if we made too much noise, we risked appearing disrespectful. It turned out silence wasn't the problem. Quite the opposite. Making it worse: we were interviewing Sen. John McCain on live television. The noise was deafening. The speeches started a few minutes before we went on the air, and as I write this, almost two hours after our first broadcast began, the speeches are still going on. While the Senator and I were struggling to hear each other, we assumed the audience could hear us. Senator McCain and I were equipped with only the standard lapel microphones -- and while I was later given a directional, noise-filtering hand-held microphone for later segments, the damage was done to our broadcast, to our massive commitment to cover a solemn event, to Senator McCain and the points he was making in responding to my questions, on our air. Sometimes in this business, the air product (what people are watching at home) isn't as bad as it seems to us in the field. In this case, it was worse. Because I was at the center of it, and I could not know how bad a viewing experience it was, I did not know to apologize while it was happening -- and I believe in apologizing immediately and forthrightly for mistakes we make. Had I known how bad it was, I would have moved heaven and earth to fix it. I would have moved the entire broadcast, on live television, inside the quiet confines of the Civil Rights museum. The McCain folks are angry, justifiably so. So are we.

At least I can apologize now. To our audience, and to Senator McCain, who went to great lengths to be with us for the live broadcast. We will endeavor to set things right with the Senator, and offer him airtime -- the quiet kind -- to allow him to be heard.

Brian Williams
Memphis, Tennessee
April 4, 2008

To our viewers:

We apologize for the unexpected audio problems at the top of the 6:30 ET broadcast. Sen. John McCain was kind enough to stay and speak with Brian again during our 7pm ET edition and you can see that interview here.

For those viewers who wrote to us asking why the interviews with Sen. Hillary Clinton and Sen. Barack Obama in the 6:30ET edition were perfectly audible when the one with Sen. McCain was not: the interviews with Clinton and Obama, as Brian mentioned during the newscast, were recorded earlier in the day.

By Brian Williams, Anchor and managing editor

I write this within view of the sad balcony -- where the ever-present wreath marks the place where the bullet struck its target 40-years ago tonight. Dr. King had apparently just finished watching the network evening news, when he stepped outside to depart for dinner. He was 39 years old.

By now perhaps you know that we have secured, for tonight's broadcast, interviews with all three Presidential candidates -- I filed a video blog from here earlier today -- and I'm proud of our news division for making the commitment to anchor the Today program and Nightly News from this hallowed spot on this important day.

All that is left is for you to watch our broadcast tonight. If you missed last night, I strongly suggest you see the 5-minute-long story that ended our Thursday broadcast, because it features color film of Dr. King that has never aired before.

We'll see you on the broadcast tonight. Have a good weekend. We'll see you again on Monday night.

By Ron Mott, NBC News correspondent

MEMPHIS -- It's a day of reflection. It's also a day of projection.

As thousands gather under rainy, cloudy skies at the former Lorraine Motel (now the National Civil Rights Museum), where Rev. Martin Luther King Jr. was gunned down 40 years ago today, people remember with fondness the hope he inspired and say they'll rededicate themselves to restoring the hope of his dream for the future.

There have been scores of events across the city throughout the week, featuring religious and civic leaders, eager to connect Dr. King's dream to a dramatically different world.

The plight of the city's striking sanitation workers is what brought Dr. King to this city four decades ago. On this day, sanitation workers marched again -- for him, for progress.

"We're still trying to get ahead," one marcher said.

Another explained: "We are still faced with a number of the same issues that we had in 1968."

Rev. Al Sharpton led what he called a "Reconciliation" march and rally, an attempt, he said, at updating Dr. King's dream for a series of new socioeconomic challenges confronting the country, particularly poverty.

Several of Dr. King's closest aides and confidantes are here, including the Revs. Jesse Jackson and Samuel "Billy" Kyles -- both of whom were with him the night he died.

Rev. Kyles said he didn't have any feelings to express then or now about how the murder of his friend and mentor affected him, adding, "You can kill the dreamer, but you absolutely cannot kill the dream."

By Lee Cowan, NBC News correspondent

FT. WAYNE, IN. Memphis is in mourning again today. The Lorraine Motel will be lit up by cameras and lights in ways eerily similar to that grim day 40 years ago when Dr. Martin Luther King lay dead or dying on that simple balcony.

All the presidential candidates will be in Memphis to offer condolences today, save one; Barack Obama. The Illinois Senator chose to speak in Indiana today instead – a long way from the civil rights struggles of the 60's. But in his absence, intended or not, may be a lesson.

It was in Indianapolis on this very day that Robert Kennedy - campaigning for the Democratic nomination himself – was dealt the task of having to inform a stunned crowd that Dr. King was gone.

In the midst of the grief, Kennedy begged for calm – as Dr. King surely would have himself. And as cities across the nation were beset with violence in the wake of the King assassination, Indianapolis remained quiet.

It was that moment that Barack Obama commemorated today. Not the shot that rang out, but how some responded in the wake of it. There will be talk of whether his choice was appropriate. Whether the first African American to have a serious shot at the White House should have visited the spot where a generation was changed.

But in the end, the unfinished business of Dr. King still reaches into every corner and every balcony in the country. What that night in Indiana 40 years ago showed, is that it's sentiment that counts, not geography.

By Brian Williams, Anchor and managing editor

In response to a post last night, I wanted to assure everyone that we will indeed air a profile of Master-At-Arms 2nd Class Michael A. Monsoor, U.S. Navy Seal, the newly-named recipient of the Medal of Honor. He recieved the Medal posthumously, for an action in Ramadi, Iraq, in September of 2006. On that day, Monsoor's team came under sudden attack, during a mission to provide covering fire for other U.S. forces. A grenade was thrown at Monsoor's position; he covered the blast, and in doing so, saved the members of his team. Members of his family spoke today. President Bush will present the medal to his family at the White House on April 8th, when we will air his profile on Nightly News.

As retired four-star General Barry McCaffrey likes to point out, we have never, in our nation's history, had a more battle-hardened U.S. military force. As he puts it, "courage (34,000 killed or wounded), leadership, initiative, intelligence, discipline, civic action." I believe its important for citizens to know stories like Monsoor's -- stories like those we chronicled on this blog for over 100 straight weekdays (always available here). As we mourn the recipients who are not with us to accept our thanks, we honor those who are.

And Dear Joan: I don't know why anyone would waste a minute of their time on my neckwear. Doesn't it seem especially silly given topics like the one I've discussed above? I've never understood it...but I'm always flattered that people chose to watch -- and they (most of them) certainly mean well!

By John Rutherford, Producer, NBC News, Washington

America paused, sighed and resumed its ways without even learning the names of the four soldiers whose deaths pushed the U.S. death toll in Iraq to 4,000.

But the grief has just begun for the families of Jose Rubio, Chris Hake, George Delgado and Andy Habsieger, all members of the Third Infantry Division who died of injuries suffered in a roadside bombing on Easter Sunday near Baghdad.

In Mission, Texas, just this side of the Mexican border, Jennifer Rubio read about the fatal blast in a local newspaper but had no idea her husband (right) was among the dead until Army officials arrived at the couple's small apartment behind City Bride & Flower Shop.

"We're still in shock," Rubio's brother Edgar told The Monitor. "It's not quite real."

In Hinesville, Ga., two Army officers knocked on Kelli Hake's door at 6 a.m. Monday morning (left).

"They said, 'We regret to inform you there's been an accident,'" she told the Stillwater News Press. "I can't remember anything after that."

George Delgado's mother in Palmdale, Calif., shared the tragic news of his death with his former principal at Desert Christian High School.

"She called us, which was very sweet," the principal told the Los Angeles Daily News. "She said they're okay, but it's very hard."

Michael Habsieger had just returned from checking on a new Collie puppy for his son Andy when he spotted a government car pulling up to their home in Festus, Mo.

"When you see that, you know exactly who they are and why they are there," Andy's mother told the St. Louis Post-Dispatch. "We're just numb."

Brenda Habsieger said her son was more than just a number (right).

"I don't like to hear about 4,000," she said. "One through 4,000 was very important, and I hope that people realize they all have faces, they all have families, and they all have a purpose in life."

Click here to view tributes to Rubio, Hake, Delgado, Habsieger and all of the 118 service members killed this year in the Middle East, including the following 12 casualties from last week:

1. Marine Lance Cpl. Dustin Canham, 21, of Lake Stevens, Wash.

2. Army Pvt. George Delgado, 21, of Palmdale, Calif.

3. Army Staff Sgt. Christopher Hake, 26, of Hinesville, Ga.

4. Army Pfc. Andrew Habsieger, 22, of Festus, Mo.

5. Army Spc. Jose Rubio, 24, of Mission, Texas.

6. Army Staff Sgt. Joseph Gamboa, 34, of Yigo, Guam.

7. Army Spc. Gregory Rundell, 21, of Ramsey, Minn.

8. Army Spc. Joshua Molina, 20, of Houston, Texas.

9. Army Staff Sgt. Keith Maupin, 24, of Batavia, Ohio.

10. Army Cpl. Steven Candelo, 20, of Houston, Texas.

11. Army Spc. Durrell Bennett, 22, of Spanaway, Wash.

12. Army Pfc. Patrick Miller, 23, of New Port Richey, Fla.

Washington Producer John Rutherford is a decorated Vietnam veteran. He also posts stories on the military at www.fieldnotes.msnbc.com (click on "John Rutherford" under "categories") and at http://john-rutherford.newsvine.com/. The tribute gallery can be found at http://www.msnbc.msn.com/id/22802019/.

By Brian Williams, Anchor and managing editor 

By Robert Bazell, NBC News chief science correspondent

My mother and her identical twin smoked enormous numbers of cigarettes from their teenage years until their deaths – my mother at age 90 and my aunt at 91.  Neither developed lung cancer.   But lest anyone think this is a recommendation for smoking,  they  both endured years of misery from emphysema and my mother (and probably my aunt) died from kidney cancer which is linked to smoking.

By Libby Leist, NBC News State Department producer

Anyone who has ever made "getting fit" a goal knows that the excuses not to work out are endless and that finding the time can be a challenge. But, imagine you are the Secretary of State of the United States.

You wake up every morning to face a punishing schedule of back-to-back meetings, lunches, dinners, speeches, ceremonies and phone calls, not to mention more travel than any other member of the President's cabinet and rarely a day off. Sounds insane, right?

Well, the May issue of Fitness Magazine offers a glimpse of how Condoleezza Rice, our 66th Secretary of State, stays fit -- both mentally and physically -- in order to keep up with the demands of her job.

In a series of photos that will be published by the magazine next week, and made available today to Nightly News and MSNBC.com, a sweaty and determined looking Secretary Rice shows off her toned physique and killer moves.

Photos by David Y. Lee for Fitness Magazine

Rice tells the magazine that she does cardio six days a week, works out with a trainer at least once a week and treats herself to a bagel on the weekends -- (yes, time to feel guilty here).

Rice gets up at 4:30 a.m. every day to work out, including on her diplomatic missions overseas, but she says its not always easy, "I'm not an automaton. I don't wakeup every morning thinking, 'Oh yeah, let's go!' I have to push myself just like anybody else."

Rice has been working on her core muscles with her trainer in order to improve her golf game, the magazine reports.

The full article hits newstands on April 8th. Check out the link to Rice's "No Excuses" workout.

By Brian Williams, Anchor and managing editor

Apologies for a cramped calendar and little time to post. I spent five hours on the set of Sesame Street today. We wrapped filming and the episode will air in August.  I'll post an air date when I know it. Until then, I'll be mum about details... though if Elmo talks, that's something I can't control.

Right now we have just broken from our editorial meeting, which morphed into a planning meeting for our Martin Luther King assasination anniversary coverage. We have a group of visiting journalists from Saudi Arabia who I must now go speak to.

About the posts over the past 24-hours, there are two conspiracy theories to knock down: first, that I would ever utter a bad word about our "regulars" -- the folks who make this blog go, and give me energy each day. I love knowing you're reading, and watching, and your loyalty means more to me than you could know. So I can't imagine ever posting a comment which would have been in any way negative. Second: I have no idea which companies make which pharmaceuticals. In my job, I have to know a lot -- and I generally like carrying around a lot of information. The parent companies of pharmaceutical products advertised on Nightly News? Not a chance.

I hope you can all join us for tonight's broadcast. I get to welcome Tom Brokaw back to the Nightly News set, to talk about a project he's justifiably enormously proud of. We'll look for you then.