06/29/2015 11:35 EDT | Updated 06/29/2016 05:59 EDT

Officials in Canmore, Alta., say last week's explosion linked to gas leak

CANMORE, Alta. - Investigators have confirmed a gas leak was behind a massive explosion in Canmore, Alta., last week.

Three people were taken to hospital with non-life-threatening injuries, another 40 were treated on scene for cuts and scrapes, and several senior citizens were shaken up when a house next to the Bow River Seniors Lodge was levelled in the blast.

Town spokeswoman Sally Caudhill says the gas leak originated in an area at the seniors' lodge that was under construction.

She says it will likely be some time before they understand what happened between the leak occurring and the explosion being triggered.

Occupational Health and Safety, Canmore Fire and potentially some insurance companies are conducting their own investigations.

Town officials continue to coordinate re-entry into the zone and they’re working with officials to make sure building and safety codes are met.

At last check, 18 homes in the immediate area were directly impacted and they’re all at various stages of re-entry at this time.

“The area is closed to the public and we’re asking people to stay away," says Caudhill. "It’s been traumatic for a lot of folks, as people can imagine so it would be really great if people were respectful."