In Kenner, La., a hearing convened Tuesday by MMS and the Coast Guard explored the immediate aftermath of the explosion. Witnesses described in dramatic detail some of the early efforts to rescue rig workers after the blast and the dogged search for survivors. Eleven men are missing and presumed dead.
Tuesday's Senate hearings were the first to look into the explosion and spill. The executives were to return Wednesday for another hearing, and more sessions are planned for next week.
The venue for the morning hearing Tuesday, before the Senate Energy and Natural Resources Committee, had once been the setting for an investigation into the sinking of the Titanic, a fact that did not escape notice.
"At that time we had a ship supposedly so technologically advanced that it could not sink," said Sen. Robert Menendez (D-N.J.). "And here we have a rig that the industry has told us so many times is so technologically advanced it supposedly could not spill."
The climate was much hotter at the second hearing, before Boxer's Senate Environment and Public Works Committee, where Sen. Frank R. Lautenberg (D-N.J.) told the executives, "Each one of you must feel terrible torment."
The hearings are expected to lead to legislation that will, among other things, increase the industry's liability for spills. A few drilling opponents at the energy committee hearing held up signs with slogans such as "Spill Baby Spill" and "BP -- Bad People."
Industry officials have expressed confidence that the relief well they are drilling will plug the leak if nothing else works. But that could take three months.
The first hearing was barely minutes underway before Murkowski urged colleagues not to retreat on new offshore drilling.
"The American people are not ready to turn their backs on offshore production -- and neither should we," she said.
But Lautenberg said later in the day, "Ultimately, what this spill shows is that offshore oil drilling simply cannot be done safely."
"We were told that 'drill, baby, drill' was the solution to our energy problems," said Sen. Shelton Whitehouse (D-R.I.). "Go tell that to the tourist economy of Florida.... Go tell that to the fishing community of Louisiana."
Times staff writer Scott Kraft in Los Angeles contributed to this report.