OSHA has announced an enforcement action against two companies after an incident at the U.S. Navy’s Naval Inactive Ships Maintenance Office in Pearl Harbor, Hawaii, killed two workers and injured two others. The victims were struck by a 7-ton buoy at the naval maintenance facility in December 2014 when a chain suspending the buoy broke, according to OSHA, which has ordered the companies to make safety upgrades.

The workers at the were repairing moorings on a barge at the time. The work was subcontracted to Healy Tibbitts Builders Inc. by Truston Technologies Inc. for the Navy.

“Our hearts go out to the family and friends of those killed and injured,” said Jeffrey Romeo, OSHA’s Honolulu area director. “Navy personnel and contractors they hired should have taken a series of common-sense steps to protect workers from facing dangerous conditions on-the-job. The best thing we can do to honor these fallen workers is to make sure similar accidents don’t happen in the future.”

OSHA reported that it has issued citations to the companies for failing to protect employees from impalement hazards, neglecting to follow written Navy procedures, exceeding the rated capacity of a wire rope sling to suspend a load, subjecting a wire rope sling to a shock load, and failing to provide safe access to the top of a concrete sinker and has proposed $46,000 in penalties.

Truston Technologies is based in Annapolis, Md., and Healy Tibbitts is based in Aiea, Hawaii, according to the agency.