ABC News sent questions to BP about the alarm system and the blowout preventers, but BP did not respond. Transocean officials said Thursday they believe it is too soon to know why the blow out preventers failed.
But members of Congress said this week they plan to investigate what went wrong with the blowout preventer beneath the Deepwater Horizon, and determine whether the thousands of other rigs that dot the American coastline pose a continuing risk.
"We saw that this device didn't work. And there were three different backup systems, each one of them didn't work. And now we're suffering the consequences," said Sen. Bill Nelson, a Florida Democrat.
"The notion that these are a fail-safe mechanism, we're finding out that they're not as safe as people were led to believe," said Sen. Maria Cantwell, a Washington Democrat. The men who worked on Transocean's Deepwater Horizon say there were told this could never happen.
"They always tell us that we have safety devices and warnings and they got ways of shutting it in," Micah Sandell told ABC News." And it don't seem like they had nothing."