EMS spokesman Adam Loria had originally identified one of the hospitalized people as an adult male but later amended that to say it was an adult female who lived in a home in the area. He said her injuries were "quite minor" and said the hospitalization was "more precautionary at this point."
Two others were taken to the local Canmore hospital in stable condition — a resident of another area home and a resident of the seniors' centre.
RCMP said the bulk of those who were injured were hit by flying glass and debris.
In addition, about 400 people in the area were displaced from their homes "due to utilities being suspended," said RCMP.
A witness named Chris told radio station CHQR that he saw the blast as he was driving down the highway.
He said he went to go see it but when he got there RCMP turned him back, saying there was the possibility of another explosion because of a gas leak.
Photos of the explosion that have been posted to social media show what appears to be construction going on at the house.
Witnesses said the blast could be felt for several blocks, debris was sent hundreds of feet into the air and a giant plume of smoke towered over the town.
A restaurant called Communitea Cafe tweeted it had been impacted by the blast.
"Likely gas explosion," read the tweet. "Seemed like it is near pond. Blew our doors open here!"
Loria said about 50 residents of the seniors' home had been briefly evacuated and EMS staff were on hand to check out the residents and make sure they were fine. They were later allowed to return home.
RCMP said the house where the explosion originated was empty at the time, and numerous other houses in the area sustained damage.
Mounties said utility workers were working in the area at the time but did not confirm a gas leak as the cause of the blast, saying the investigation is ongoing.
(CHQR, CTV Calgary, The Canadian Press)