The Coast Guard Investigative Service served search warrants on Truth Aquatics, the owner of the diving boat that was swallowed up by flames off the California coast on Labor Day, Santa Barbara County Sheriff's Office spokesman Lt. Eric Raney told CNN.
"This is all just part of the ongoing investigation," Raney said. "The Coast Guard was assisted by ATF which is investigating the fire and the FBI which has expertise in criminal investigations."
Of the 39 people who were aboard the 75-foot dive boat Conception that weekend, only five crew members were found alive. The others, who were in the lower sleeping deck, likely got trapped when the fire blocked their escape, authorities have said.
Preliminary indications are that the victims' cause of death was smoke inhalation and that the passengers died "prior to being burned," Santa Barbara County Sheriff Bill Brown said Friday.
Thirty-three bodies have been recovered and one remains missing, the sheriff's office said.
Recovery efforts suspended
Friday, the sheriff's office suspended salvage and recovery efforts because of winds and increased currents, Raney said in a news release.
Recovery efforts for the last missing person have also been suspended and will resume when weather conditions improve, the release said.
Authorities hope to resume operations on Tuesday, Coast Guard Pretty Officer Mark Barney told CNN. Meanwhile, the vessel remains secured underwater.
"We are just waiting for Mother Nature to cooperate," Barney said.
Investigation of similar boat leads to safety concerns
After investigating a similar boat owned by the same company, National Transportation and Safety Board (NTSB) board member Jennifer Homendy told CNN she has several safety concerns, including whether there is proper equipment for detecting and suppressing fire.
"We're looking into the adequacy of smoke detectors and were there enough fire extinguishers," Homendy said.
The escape hatch in the lower bunk level on the Vision-- the similar boat -- was small, difficult to see, access and maneuver, she said.
The NTSB will be evaluating whether there were "issues with evacuation or responses" or "escape survival factors," Homendy said. She said officials had already interviewed the owner-operator of the dive boat, but didn't offer any further details.
The Labor Day disaster may well spark changes in regulations of commercial dive boats and related vessels, said retired US Coast Guard Capt. Kyle McAvoy, a marine safety expert with Robson Forensic who specializes in marine incident investigations.
"A lot of regulatory and policy and safety initiatives are driven by tragic events such as this," McAvoy told CNN. "The expression is that a lot of regulations are written in blood."