Investigators are working to determine the cause of death of a Questar employee who was working alone at a job site near Rock Springs . Deputies and first responders were dispatched to the location around . An ELM Locating employee who was working nearby spotted the man in a hole at the Questar job site and called 9-1-1. After flagging down a Fed Ex driver, the two men were able to life the unconscious man out of the hole and began CPR but he was unresponsive. Responders were unable to revive him. The man was 40-year-old Jason Crompton. Crompton was working alone to locate a natural gas pipeline tracer line using a shovel and garden hoe in a muddy hole about 4 feet deep and 20 inches wide. No foul play is suspected and the investigation has been turned over to the Wyoming Occupational Safety and Health Administration. Investigators hope to determine cause of death through the autopsy scheduled for .