Technician Tells Investigators Oil Rig Alarm System Disabled on Day of Blast

Williams testified that he had asked before about the settings and was told the company didn't want a false alarm waking people at night.

Williams said that if the system had been fully active, an alarm likely would have sounded before the explosion, which happened on the night of April 20. The rig sank 2 days later. Since then, millions of gallons of oil have poured into the Gulf.

Mike Williams, chief engineer technician aboard Swiss-based Transocean Ltd's rig, said the general alarm that could have detected the cloud of flammable methane gas that enveloped the rig's deck on April 20 was "inhibited."

"They (rig managers) did not want people woke up at three o'clock in the morning from false alarms," Williams told a six-member federal board in the New Orleans suburb of Kenner, Louisiana.