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Is it working?

The Gulf oil spill is turning many of us into armchair engineers. Like a lot of people around the world, I've been watching the live internet feed of the oil gushing from beneath the Gulf and trying to discern changes of color that might indicate whether the "Top Kill" fix is working. We expect a definitive assessment of the operation from the company by the time we hit air tonight, but indications so far are that it is not working. Our Anne Thompson choppered over the spill today for an exclusive look and chat with BP's chief operating officer. Anne will be live tonight to share the pictures and tell us what the next step might be.

We'll also look back on the life of Hollywood legend Dennis Hopper who died today in Los Angeles and get to the bottom line of how an armed American drone killed 23 Afghan civilians in an attack last February.

I hope you can join us later for NBC Nightly News.