OSHA found that “the operator of three Massachusetts waterproofing contracting companies could have prevented an employee from suffering fatal injuries... when part of the foundation broke and fell on the worker in a 5- to-6-foot-deep trench beneath the foundation of a Hanson residence,” the agency said in a statement on Friday.

The employer, Aleckssandro Tomaz Pereira, of Woburn, operating as Boston Concrete Corp. LLC, VMT Contractor LLC and Boston Concrete and Remodelling LLC “exposed employees to cave-in, caught-between and structural collapse hazards by failing to protect the trench and the building foundation against collapse,” the statement read.

“Aleckssandro Tomaz Pereira should never have placed workers in this trench until the excavation and the building’s foundation were guarded against collapse, workers were properly trained, water was removed from the trench and an exit ladder was provided,” OSHA Area Director James Mulligan, of Braintree, said in the statement. “This tragedy was entirely preventable.”

Pereira was cited for two willful and six serious violation, the statement read. OSHA proposed $283,115 in penalties.