Oil rig explosion

NEW ORLEANS, May 13 (UPI) -- The Gulf of Mexico drilling rig explosion that started a massive oil leak came about through a "calamitous series" of failures, a U.S. congressman said.

Officials from several companies with links to the Deepwater Horizon oil platform appeared before congressional committees this week. The platform exploded in flames April 20, killing 11 workers. Since then about 5,000 barrels of oil have been spewing the gulf daily.

U.S. Rep. Henry Waxman, D-Calif., and chairman of the House Energy and Commerce Committee, said some 100,000 pages of documents were submitted by companies, including rig operator BP, platform owner Transocean and contractor Halliburton, and indicate how the tragedy started.

"This catastrophe appears to have been caused by a calamitous series of equipment and operational failures," Waxman said.

Another committee member, Rep. Bart Stupak, D-Mich., said the blow-out preventer, meant to keep such a disaster from occurring, had a leak in a hydraulic system and a dead battery in a device designed as backup to shut down the oil flow, as well as other issues.

BP, in a release Thursday regarding efforts in the gulf to close off the spewing wellhead, said it was still working to get the blow-out preventer to operate. One possible solution involved injecting "material of varying densities and sizes" into the blow-out preventer to seal the wellhead and pumping other fluids into the well to further halt the oil flow.