A boat with an oil boom tries to contain oil spilled from the explosion and collapse of the Deepwater Horizon oil rig Friday, approximately seven miles from where the rig sank in this aerial photo from the Gulf of Mexico.

New Orleans ? Federal regulators did not need this week’s explosion aboard a state-of-the-art rig to know the offshore drilling industry needed new safety rules: Dozens of deaths and hundreds of injuries over the last several years had already convinced them that changes were needed.

The U.S. Minerals and Management Service is developing regulations aimed at preventing human error, which it identified as a factor in many of the more than 1,400 offshore oil drilling accidents between 2001 and 2007.

Search suspended

What caused Tuesday’s massive blast off the Louisiana coast is unknown. On Friday, Coast Guard officials suspended the three-day search for 11 workers missing since an explosion rocked the Deepwater Horizon, saying they believe the men never made it off the platform.

Coast Guard Capt. Peter Troedsson said he spoke with all the workers’ families about the decision to suspend the search before announcing it to the media.

The Coast Guard says it will resume the search if any ships in the area see anything, but the workers’ chances of survival had seemed slim well before Friday afternoon’s announcement.

The 11 missing workers came from Texas, Louisiana and Mississippi. The Coast Guard has not released their names, though several families have come forward.

Scott Bickford, a lawyer for the family of missing worker Shane Roshto, said Roshto’s wife, Natalie, had been staying with other workers’ relatives at a hotel in suburban New Orleans but returned home to Liberty, Miss., on Friday morning.

“Natalie has pretty much accepted the fact that her husband is not coming back,” Bickford said.

Steven Newman, CEO of Transocean Ltd., which owns the rig, said Friday night that 8 of the 9 missing Transocean workers were part of the crew that operated the platform’s drills. The other 2 workers were employees of a BP contractor. Newman said the company would continue to assist investigators in determining the cause.

As the search was ending, oil company crews were trying to clean up the environmental mess created by the Deepwater Horizon, which finally sank Thursday.

The other 115 crew members made it off the platform; several were hurt but only two remained hospitalized Friday. The most seriously injured worker was expected to be released within about 10 days.

Review’s findings

An MMS review published last year found 41 deaths and 302 injuries out of 1,443 oil-rig accidents from 2001 to 2007. An analysis of the accidents found a lack of communication between the operator and contractors, a lack of written procedures, a failure to enforce existing procedures and other problems.

As a result of the findings, the MMS is developing new rules that would require rig operators to develop programs focused on preventing human error, an area that received relatively little attention in the past. The agency also suggested audits once every three years on programs to prevent human error.

BP PLC, which leased the Deepwater Horizon, opposes what it says are “extensive prescriptive regulations.”

Environmentalists say that while new technology continues to improve, people still have to oversee those devices and human error remains a widespread problem.

“You can’t outlaw human error,” said Richard Charter, a senior policy adviser with Defenders of Wildlife, who has been involved in drilling issues for 30 years.

Opponents of President Obama’s plan for more offshore drilling, particularly off the East Coast, say the explosion on the Deepwater Horizon should be taken as a warning to slow the fervor to “drill, baby drill.”

“I would hope it would serve as another wake-up call on this issue that there is no such thing as safe oil drilling,” said Sara Wan, a member of the California Coastal Commission, a state regulatory agency.

Obama showed no sign of budging Friday. Spokesman Robert Gibbs said the president still believes increasing domestic oil production can be done safely without harming the environment.