NEW ORLEANS (AP) — The Coast Guard was searching Wednesday for a crew member who went missing after an explosion injured six members of a dive-support team working on a pipeline in the Gulf of Mexico.

Coast Guard helicopters transported the six injured crew members to hospitals in Lafayette and Houma after Tuesday night’s explosion about 15 miles south of Marsh Island in Iberia Parish.

Three of the six injured workers were later released from the hospital, according to an official from the company that owns the vessel. Neither the Coast Guard nor the company, Chet Morrison Contractors of Houma, released conditions for the three men who remained hospitalized Wednesday.

A seventh crew member aboard the 150-foot Jillian Morrison was missing after the blast.

Chet Morrison, the company’s CEO, called it a “tragic accident.”

“We’re doing everything we can to assist the families,” he added. “All company personnel are grieving and are keeping the victims and their family members in our thoughts and prayers.”

Thirty-two people were aboard the vessel at the time of the explosion. The Coast Guard didn’t immediately release the names of the missing or injured crew members.

A Coast Guard spokesman, Petty Officer Thomas Blue, said investigators were trying to determine if the pipeline exploded or if the blast occurred aboard the boat.

“That’s why we’re sending out an investigator, to find out exactly what happened,” Blue said.

However, Morrison said the explosion apparently occurred in the boat’s engine room. The vessel was anchored to the bottom of the Gulf, but nobody was in the water at the time of the blast, he added.

“They were in the field as part of routine connection work associated with some part of the pipeline,” Morrison said.