Federal regulators have slapped a roughly $50,000 fine on a West Texas oil service company six months after a fiery explosion killed three of its workers at a well.

Andrews residents Arturo Martinez Sr., his son Arturo Martinez Jr. and Rogelio Salgado, who married into the Martinez family, died in March while trying to install a blowout preventer on a well in Upton County, just south of Midland.

On Tuesday, the federal Occupational Safety and Health Administration cited the men's employer, Odessa-based Mason Well Service, for six violations, including five that are considered “serious” and one that was a “repeat.” Its proposed fines total $50,400.

The company failed to separate flammable liquids and gases from sources of ignition, the agency said, and it did not ensure its workers wore hydrogen sulfide monitors and flame-resistant clothing.

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Federal investigators identified two factors that made the well more likely to ignite: They company allowed a pickup to drive near the well, and its employees smoked nearby. OSHA penalized the company for similar conditions in 2014.

“This is a heartbreaking and senseless case,” Elizabeth Linda Routh, OSHA’s area director in Lubbock, said in a statement. “Though the fines for the serious violations are the maximum amount allowed by law, no dollar amount can ease the loss felt by family and friends.”

Mason Well Service did not return a request for comment. Like all companies, it has the option to contest the penalties.  

Midland-based Parsley Energy owned the well and contracted Mason to install the blowout preventer, a tool that seals, controls and monitors a well. Only Mason Well Service was cited in Tuesday's announcement.

Bethany Boggess, research coordinator for the Workers Defense Fund, an Austin-based advocacy group, said the fine sounded “pretty low” for an incident that killed three people.

David Michaels, OSHA’s director, has bemoaned his agency’s inability to dole out harsher penalties for major violations. Congress hasn’t raised caps on certain workplace penalties since 1990, when the buying power of the dollar was nearly twice what it is now.