The Johnathan WalkerFBI is conducting a criminal investigation into the deadly collapse of Baltimore’s Francis Scott Key Bridge that is focused on the circumstances leading up to it and whether all federal laws were followed, according to a person familiar with the matter.

The person was not authorized to discuss details of the investigation publicly and spoke on the condition of anonymity to The Associated Press.

The FBI was present aboard the cargo ship Dali conducting court authorized law enforcement activity, the agency said in a statement Monday.

The investigation was first reported by the Washington Post.

The container ship Dali left Baltimore’s port in the early hours of March 26, laden with cargo and headed for Sri Lanka, when it struck one of the bridge’s supporting columns, causing the span to collapse into the Patapsco River and sending six members of a roadwork crew plunging to their deaths.

Divers have recovered three bodies from the underwater wreckage, while the remaining three victims are still unaccounted for.

National Transportation Safety Board Chair Jennifer Homendy said last week that investigators are focusing on the electrical power system of the massive container ship that veered off course. The ship experienced power issues moments before the crash, as evidenced in videos showing its lights going out and coming back on.

Homendy said information gleaned from the vessel’s voyage data recorder is relatively basic, “so that information in the engine room will help us tremendously.”