The remains of 1070 Esdras Pl. as seen not long after a natural explosion that happened March 24, 2011. (CBC News)

Police have charged a construction site supervisor with criminal negligence causing death in connection with the natural gas explosion that killed a 75-year-old Windsor man last year.

On March 24, 2011, a construction crew contracted by the City of Windsor was replacing the main sewer line and sewer service lines to each home on Esdras Place.

Police said that while digging a pit in front of 1070 Esdras Pl., the crew exposed the Union Gas main natural gas line, which had been clearly marked with "locates."

Police said the crew did not follow Technical Standards and Safety Authority (TSSA) excavation guidelines and, as a result, the underground natural gas service line to 1070 Esdras Pl. ruptured, causing natural gas to leak underground. The gas seeped through the porous cinder block walls while homeowner Ronald Nelson was out.

At 4 p.m. that day, Nelson returned. Shortly after, an explosion occurred and caused the home to become engulfed in flames. Nelson died of smoke inhalation.

According to police, several people at the construction site, including an on-site City of Windsor employee, told the site supervisor of the construction crew they could smell natural gas.

The site supervisor allegedly dismissed the odour, and work continued, without Union Gas being notified of the possible damage to the gas line, police said.

Windsor Police Staff Sgt. Gerry Corriveau said while witness statements vary a little, people began noticing the smell of natural gas sometime between 9 a.m. and lunch time.

"You can't go back and change history and guarantee that things would've been different, but it's certainly the investigators' opinion that if work would've been stopped, the gas company would have been notified, proper precautions would have been taken," Corriveau said.

Windsor Police charged 44-year-old Alipio Gaspar with criminal negligence causing death. He was arrested Feb. 1.

Corriveau broke news of the arrest to members of Nelson's family. "They're still quite distraught about the death of their father," Corriveau said. "It's been a very long process for them. I'm sure that in some sense it may have presented them some closure."

Gaspar has been released on a promise to appear in court March 6.