New Orleans ? A tugboat pushing two barges hit an offshore natural gas pipeline Thursday, causing an explosion that killed three people, left three missing and sent flames shooting 100 feet high, the Coast Guard said.

The tug and barges hit the gas line about 12:30 p.m. in West Cote Blanche Bay, about two miles from shore and 100 miles southwest of New Orleans, said Petty Officer 2nd Class Nyx Cangemi.

The tugboat had two people on it, and six people were on the barge, Cangemi said. Coast Guard rescue crews recovered three bodies and two survivors. Three people remained missing.

One survivor was severely burned and taken to a hospital, said Coast Guard spokeswoman Veronica Bandrowsky. The other was not injured, she said.

A helicopter crew was to remain out seeking the three missing people until midnight and return at first light today, Bandrowsky said, and water patrol officers of a local parish were to be out through the night.

Gulfport Energy Corp. said the accident involved two contracted vessels doing work for the company in a large energy field.