BATON ROUGE, LA -- The U.S. Coast Guard suspended their search for four people on board a helicopter that crashed into the Gulf of Mexico, while departing an oil platform, Thursday morning.

Although the crash is not a closed case, crews will not resume a search unless they receive new information said Petty Officer Jose Hernandez, a spokesperson for the Coast Guard's 8th District, which is headquartered in New Orleans. New information includes additional debris or a body.

"It is always a difficult decision to suspend a search," said Lt. Cmdr. Kevin Keefe, Coast Guard Sector New Orleans Search and Rescue Mission Coordinator.

The helicopter's pilot and three oil workers went down around 8:40 a.m. CST Thursday about 10 miles (16 kilometres) offshore of Southwest Pass, a shipping channel at the mouth of the Mississippi River southeast of New Orleans. Helicopters routinely transport workers to and from oil platforms in the Gulf.

Weather didn't appear to be a factor in the crash, Hernandez said, as there were no reports of storms in the area Thursday. The National Transportation Safety Board said it is investigating the crash. NTSB said it should have a preliminary report in a few weeks.

Crews in a boat and a helicopter searched for eight hours, covering an area of roughly 180 square miles (460 square kilometres). Hernandez said that crews did find debris, but no people. Photos of the debris released by the Coast Guard showed a cluster of cylindrical yellow objects bobbing in the water.

One of the missing workers is 36-year-old David Scarborough of Lizana, Mississippi, according to his wife, Lacy Scarborough. She told the Sun Herald newspaper that they are expecting a baby, and that her husband recently got a job promotion.

On Thursday, she said her family was praying that her husband and the others would be rescued safely.

"He enjoyed his job and his coworkers," she said.

Hernandez said the oil platform is operated by Houston-based Walter Oil and Gas. A spokesperson for the company did not return a request for comment by The Associated Press.

The Coast Guard said the helicopter is owned by Rotorcraft Leasing Company, which did not respond to requests for more information.

Two weeks ago, another of Rotorcraft's helicopters crashed off the Louisiana coast while attempting to land on an oil rig platform. The Coast Guard rescued three people. That Dec. 15 crash occurred south of Terrebonne Bay, roughly 60 miles (97 kilometres) west of the area the Coast Guard was searching Thursday.