Two people have been killed and several others are in hospital after a float plane crashed on a street in Yellowknife.

Nine people were on board the Twin Otter plane, said Chris Krepski, a spokesman with the Transportation Safety Board.

Witnesses said the plane's two pilots died in the crash, despite efforts to save their lives.

Seven others were transported to hospital. Two were in critical condition while the other five were in stable condition.

At least one of the injured was being flown to hospital in Edmonton for treatment.

The plane crashed at around 1 p.m. local time between two buildings in an area of Yellowknife known as Old Town.

Debbie Doody, co-owner of the Dancing Moose Cafe, said the nearby crash sounded "kind of like thunder."

"I can't really explain it. We all just jumped," she said. "The ladies sitting there in the restaurant, they saw the whole plane go right by the window. They jumped up and screamed and there was this giant crash and the power went out."

Witnesses rushed out and wound up performing CPR on the two pilots, Doody said, but they were unable to save them.

"It's really upsetting," she said.

Don Bubar, CEO of Avalon Rare Metals, said three of his company's employees and four of their guests were on board the plane. They had been flying back from Thor Lake, a community about 100 kilometres east of Yellowknife.

"Everyone's OK that were amongst the passengers," he said from Toronto, where his company is based. "They have suffered injuries, understandably, but not life-threatening."

RCMP closed off roads in the neighbourhood around the downed aircraft, which is owned by Yellowknife-based Arctic Sunwest Charters.

The company is not commenting on the crash, and the Transportation Safety Board said two investigators will visit the site.

Yellowknife Mayor Gord Van Tighen told APTN the plane may have clipped a power line moments before the crash.

Van Tighen said the incident would be felt across the community.

"Our librarian lives in a house near there, friends of mine live on the street, I live a block away. So yeah, it was close to home," he said

"Everybody in town will be hit with this, one way or another."

With files from The Canadian Press