NEW ORLEANS — A contract worker has pleaded guilty to violating the federal Clean Water Act in connection with a deadly oil platform explosion off Louisiana’s coast.

Don Moss, of Groves Texas, pleaded guilty Thursday.

Prosecutors said in court documents that Moss was among personnel who failed to ensure conditions were safe for welding on the platform owned by Black Elk Energy Offshore Operations.

A worker welding a pipe on Nov. 16, 2012, ignited oil vapors, causing an explosion and fire that killed three workers and led to a discharge of oil into the Gulf of Mexico.

Houston-based Black Elk was sentenced to pay a $4.2 million fine last year after pleading guilty to violating federal safety and pollution laws.

Moss’ sentencing is June 28.