An Edmonton man returned to work just one day after spending roughly three hours trapped inside a construction site trench that collapsed in on him.

On Thursday afternoon, an employee with Orion Environmental was installing a shoring cage, which keeps workers safe in trenches, as part of a sewer repair job with GS Construction when the trench collapsed in on him.

Nick Thomas, a construction worker who rushed to the scene, told CTV Edmonton the man was buried up to his helmet in sand and rubble.

“He was spitting the sand out, essentially,” Thomas said. “He had my one hand, so my other hand just kept clearing [the dirt] away and asking him if he could still breathe.”

Thomas stayed with the man until emergency crews arrived. As luck would have it, Edmonton Fire Rescue’s technical rescue crew happened to be doing trench rescue training that day, something firefighter Shane Mulligan called a “sheer coincidence.”

“Only the top of his helmet was visible and his fingers,” said Mulligan. “At that moment, we saw his hand moving, so we knew he was alive and breathing.”

After nearly three hours, the rescue crew freed the man, who was transported to hospital, but returned to work Friday on modified duty.

“He was basically unharmed and so for us, that is a huge win,” said Rob Kulchitsky, station captain with Edmonton’s fire rescue department.

The incident is under investigation by Occupational Health and Safety. The department says GS Construction has not had a safety issue in at least the past five years.

“Obviously something went wrong,” said Terran Sandwith, president of GS Construction. “Obviously something happened there that (we’ve) got to get to the bottom of.”

“This has never happened to us, so definitely a little bit of a shock. We’re going to leverage this as a learning lesson and trying to be better going forward.”

Orion Environmental did not return a CTV Edmonton request for comment

With a report from CTV Edmonton’s Bill Fortier