Breaking News from AP

GRAND ISLE, La. — An offshore oil rig exploded Thursday in the Gulf of Mexico, and the Coast Guard was responding to reports of people in the water.

The explosion sparked a fire aboard the oil rig, owned by Mariner Energy. It occurred west of the site of the April blast that caused the massive BP oil spill.

A commercial helicopter company reported the blast around 9:30 a.m. CDT Thursday, Coast Guard Petty Officer Casey Ranel said. Seven helicopters, two airplanes and four boats were en route to the site, about 80 miles south of Vermilion Bay along the central Louisiana coast.

The Coast Guard said initial reports indicated all 13 crew members from the rig were in the water. One was injured, but the others were said to be OK and awaiting rescue.

The platform is in about 2,500 feet of water, the Coast Guard said, and was not currently producing.

Roughly 206 million gallons of oil from an undersea well spilled into the Gulf after BP's Deepwater Horizon rig exploded April 20, killing 11 workers. That was the biggest maritime oil spill in history.

Mariner Energy is one of the leading independent oil and gas exploration and production companies in the Gulf of Mexico. As of the start of the year, the company had interests in approximately 240 blocks on the continental shelf and 100 blocks in deepwater.