OSHA has issued serious confined space citations to a construction company in Saipan, Northern Mariana Islands, after three of its employees died from exposure to hydrogen sulfide gas.

The tragedy occurred on July 7, 2017, as USA Fanter employees were working in and around a well that was not identified as a permit-required confined space. When one employee was overcome by fumes after entering the well, two other employees attempted to rescue him, and were also overcome by the gas.

The ensuing OSHA investigation found that the company failed to conduct atmospheric testing, control atmospheric hazards, provide rescue and emergency services, and provide employee training. The company faces $59,576 in proposed penalties.

“This case demonstrates how failing to follow necessary procedures in confined spaces can have deadly consequences,” said OSHA Regional Administrator Barbara Goto. “Employers must recognize the dangers of assigning work in confined spaces, and take appropriate precautions to protect workers’ safety and health.”