NEW YORK (CNNMoney.com) -- Employees on the Deepwater Horizon oil rig that exploded April 20 all had the ability to stop the drilling process at any time but ignored red flags, BP and Transocean executives told lawmakers Thursday.
"Any employee, anywhere at any level, if they have any concern about safety, has the ability and, in fact, the responsibility to raise their hand and try to get the operations stopped, whether that's our operations or a contractor's operations," Lamar McKay, chairman and president of BP America, told the House Natural Resources Committee.
Transocean president and CEO Steve Newman said his company - which owned the oil rig - gives all its employees "stop work authority" to call a "time out for safety." He said the company even takes pictures of employees and distributes them across the entire organization, to recognize those who have called so-called time-outs.
But why then did no one say "stop?"
Lamar acknowledged that hours before an explosion sunk the rig, killing 11 workers and sending oil gushing into the Gulf of Mexico, there were warning signs that went ignored.
"I do think there is a significant period of time where there were signals and there was a cumulative effect of those signals that were not recognized," he said.
Lawmakers questioned both McKay and Newman about an alleged argument that took place between BP's site manager and the Transocean team over a procedure hours before the blast.
But both McKay and Newman said they didn't know anything about the argument, other than what was reported in the press Wednesday.
The hearing was one of several oil-related sessions on Capitol Hill this week as Congress investigates the cause of the Gulf Coast spill.
At a news conference Thursday, President Obama said the government will extend a moratorium on permits to drill any new deepwater wells for at least six months. Offshore drilling permits have been suspended since April, after the Deepwater Horizon explosion.
Newman said he would support a moratorium for six months, calling it a "prudent" pause while investigators still search for the cause of the explosion, but he still believes in the long-term importance of offshore drilling.
The hearing comes a day after BP started a so-called "top kill" procedure aimed at plugging the leak. McKay said at Thursday's hearing that he does not know whether the procedure is working, but the company will continue to report on its progress.
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