The Honolulu Medical Examiner’s Office identified the two workers killed in Wednesday’s Pearl Harbor barge accident as Joefrey Andrada, 42, and Justin Saragosa, 30.

The medical examiner’s office said the autopsies were conducted Thursday, but the preliminary cause of death hadn’t been certified yet.

The two civilian contract workers were killed and two others were injured while working on the barge with a crane at the Naval Inactive Ship Maintenance Facility off Waipio Peninsula.

The four civilians were working on a floating concrete block when a 10,000-pound buoy fell about 70 feet, partially hitting two of them. The two others were injured while getting out of the way to avoid being hit.

Andrada suffered traumatic injuries and was pronounced dead, and Saragosa experienced a critical head injury.

The workers were employed by Healy Tibbitts Builders Inc., which specializes in marine construction.

They were replacing a buoy on the 820-foot decommissioned amphibious ship Tarawa, which uses a number of the circular white buoys, officials said.

A plate attached to the buoy reportedly failed. The accident was reported at 10:19 a.m.

“We are devastated to learn of the loss of two members of the Healy Tibbitts family,” Rick Heltzel, company president, said in a statement Wednesday. “Our thoughts and prayers are with the families at this extremely difficult time. We do not yet know what caused the incident and will be working with the Navy and other agencies to investigate this tragic event.”