Five companies now are facing $795,254 in fines after an OSHA investigation discovered 55 violations.

“This tragedy could have been prevented if the employers had followed proper confined space procedures and implemented appropriate safety measures,” said OSHA Regional Administrator Kurt A. Petermeyer, in a statement.

The agency cited ship repair contractor First Marine LLC; insulation contractor Thermal Control and Fabrication Inc.; temporary staffing companies Hutco Inc. and Day Help LLC (doing business as Wise Staffing Group); and blasting and painting contractor Joe Rupcke.

First Marine LLC has been placed in the agency’s Severe Violator Enforcement Program.

The investigation found that the explosion occurred when employees were cutting and welding in an atmosphere containing flammable gases. OSHA issued citations for failing to test confined spaces before entry; train workers on confined space entry operations; label chemical containers; exposing employees to asphyxiation, fire, explosion, chemical, trip, and drowning hazards; and allowing hot work/welding to be performed without testing for an explosive atmosphere.

The companies have 15 business days from receipt of the citations and proposed penalties to comply, request an informal conference with OSHA’s area director, or contest the findings before the independent Occupational Safety and Health Review Commission.