A Florida utility contractor fined by OSHA twice since January 2017 in connection with job site incidents that killed four workers is again facing proposed penalties over safety issues.

Douglas N. Higgins was recently issued proposed fines of $18,659 stemming from an inspection that occurred at a Naples, Florida, job site in December. The inspection was part of OSHA’s National Emphasis Program on Trenching and Excavation. According to a United States Department of Labor press release, OSHA inspectors found several safety violations, including employees working in trenches without cave-in protection.

This follows two other incidents in the past year and a half that resulted in both fines and fatalities for Douglas N. Higgins.

The company was fined $162,596 for a November 2017 incident in which a worker installing sewer lines suffered fatal injuries when a steel plate fell on him.

Prior to that, the company was fined $119,507 for several violations — i.e. failure to purge or ventilate a confined space before entry and failure to provide necessary rescue and emergency equipment for employees — in a January 2017 incident that killed three workers on job site in Key Largo, Florida. Three men were all overwhelmed by toxic gases in a manhole while investigating reports of a sewage backup. One man entered the manhole and became unresponsive, and the same thing happened to the other two men when they attempted to rescue him. Atmospheric testing afterward revealed lethal levels of hydrogen sulfide and carbon monoxide.

“Despite being recently cited for violations that contributed to four worker fatalities, this employer continues to disregard well-known safety and health requirements,” Condell Eastmond, OSHA Fort Lauderdale area office director, said in a press release. “Employers involved in excavation work must follow safety procedures to ensure that workers are properly protected from a trench collapse and other trench hazards.”