[Updated at 8:00 p.m.] BP resumes "top kill" procedure late Thursday afternoon after suspending operation for 16 hours Wednesday night, BP executive Doug Suttles said.

"Nothing has actually gone wrong or unanticipated," Suttles said. BP spent most of Thursday evaluating the first round of pumping. The light-brown material seen flowing out of the well throughout Thursday was the previously pumped fluid mixed with oil, he said.

[Updated at 11:13 a.m.] The Gulf oil spill is the worst in American history, estimates by government scientists suggest.

[Updated at 10:54 a.m.] Two survivors of the oil rig explosion April 20 that triggered an underwater oil gusher in the Gulf of Mexico, along with the father of a man who died, urged members of a House committee Thursday to hold the rig's owner and the oil company leasing the rig accountable for the disaster.

[Updated at 10:38 a.m] Interior Secretary Ken Salazar told members of a key House subcommittee Thursday that he remains "very confident and resolute that we will solve the problem" of the oil spill in the Gulf of Mexico.

[Updated at 10:24 a.m.] Interior Secretary Ken Salazar was told Thursday by Virginia Democratic Rep. Jim Moran, the head of a key House Appropriations subcommittee, that he "will be responsible" for ensuring there isn't a repeat of the oil spill "catastrophe" in the Gulf of Mexico.

[Updated at 10:22 a.m.] The Gulf of Mexico undersea gusher is spewing oil at a rate of 12,000 to 19,000 barrels a day, U.S. government scientists estimated Thursday.

That's more than twice as much as previous estimates, which put the rate at 5,000 barrels per day.

The government had two separate teams of scientists estimate the rate of flow using two different methods, U.S. Geological Survey Director Marcia McNutt told reporters Thursday.

One team looked at the oil on the surface and came up with the estimate of 12,000 to 19,000 barrels per day.

A second team used a different method and came up with a range of 12,000 to 25,000 barrels per day, McNutt said. The official estimate uses the range where the estimates overlap.

[Posted at 10:20 a.m.] BP's "top kill" procedure is going as planned and according to expectations, U.S. Coast Guard Adm. Thad Allen, the government's point man in the Gulf of Mexico oil spill response, said Thursday.

In response, a BP official told CNN, "We appreciate the optimism, but the top kill operation is continuing through the day today - that hasn't changed. We don't anticipate being able to say anything definitive on that until later today."