Calgary p​olice had previous experience with the gunman killed in Huntington Hills after a standoff that had the neighbourhood on lockdown for hours — but none of the incidents was related the recent string of gang violence, according to Chief Roger Chaffin.

Chaffin said more than a dozen officers responded to the "extremely dynamic" situation in the northwest community after reports first rolled in at about 4:40 p.m. MT Sunday of a gunman firing from a home, apparently at anything and everything.

A bus driver first called 911 after a round went through the transit vehicle's windshield, Chaffin said.

The situation "escalated" when the suspect left the home and police responded with gunfire of their own, the chief said.

"Officers set up containment while shots continued to be fired," Chaffin said.

"Several attempts were made to resolve the situation peacefully, however the suspect exited the residence and the situation escalated resulting in the discharge of a service firearm, resulting in killing the suspect."

Sources told CBC News the gunman, in his 50s, was in a wheelchair and had numerous firearms in his possession.

Chaffin said the motivation is unknown and police are not releasing the gunman's identity.

No one else was injured during the incident, Chaffin said, and the Alberta Serious Incident Response Team (ASIRT) is investigating.

Several blocks of the community were closed to traffic for hours on Sunday night.

Police had warned residents near the 1000 block of 78th Avenue N.W. to take cover in their basements during the shooting incident.

Kevin Brennan, who lives about 150 metres from the suspect's house, was out walking with his wife and 14-month-old daughter when an officer in an unmarked car told him to go home and stay inside in the basement.

Kevin Brennan

Kevin Brennan, and his wife and 14-month-old daughter, live about 150 metres from where the incident took place. He says he heard 5 shots. (Meghan Grant/CBC)

"It was scary," said Brennan, who used to be a police officer in Ireland.

"I heard five shots and it sounded to be from a pretty small-calibre gun from where I was."

Ken Cooper, who has lived in the community for about 10 years, said he heard about half a dozen gunshots in what has otherwise been a quiet neighbourhood.

"Police come up the street now and again, but very seldom do we get stuff like this happening," Cooper said.