BOSTON (CBS) – The owner of Atlantic Drain Services is being charged with manslaughter and misleading the investigation into to the death of two employees who were trapped in a flooded trench following a South End water main break.

Suffolk District Attorney Dan Conley announced Wednesday that Kevin Otto and Atlantic Drain Services have each been charged with two counts of manslaughter, one count of misleading an investigator, and six counts of concealing a record following the deadly October incident on Dartmouth Street.

Conley said federal requirements mandate that trenches deeper than five feet must be shored up using metal or wood. The Dartmouth Street trench was 14 feet deep but not secured.

Robert Higgins and Kelvin Mattocks died when they became trapped beneath the water in the trench following a water main break.

Otto and Atlantic Drain Services had two prior Occupational Safety and Health Administration violations in the past 10 years, and as a result were required to undergo training.

Prosecutors allege that the company doctored paperwork to appear that employees had attended training when they had not.

Conley said Atlantic Drain Services “gambled with their employees lives and safety.”

“That isn’t an accident. That isn’t negligence. That’s wanton and reckless conduct, and we believe it cost two men their lives,” Conley said.

A grand jury made the indictment on manslaughter charges against Otto and the company.