Staff at a summer camp in northeast Edmonton did everything right Tuesday night when a severe thunderstorm swept through, knocking down teepees and sending 21 people to hospital, say camp officials.

"The staff did a fabulous job," said  Michael Doherty, Our Lady Queen of Peace Ranch foundation president and CEO.

"Could it have been a lot worse? Yes, it could have. I credit the staff for how they responded and how they got the kids quickly to the hall."

Staff began evacuating the 30 teepees in which 250 youngsters were staying at 9 p.m., Doherty said.

The storm hit 10 minutes later.

si-doherty-peace-ranch_1

Foundation CEO Mike Doherty praised staff for evacuating campers from the teepees as the thunderstorm moved in. (CBC)

Camper George Suian-Johnson, 15, said the storm came quickly.

"I had everybody's sleeping bag on my shoulder," he said describing the evacuation to the main building.

"This other guy named Dakota was carrying all the mats, so he had six mats like this and we weren't even 10 steps away and [a teepee] fell over."

Doherty said staff  knew about the severe thunderstorm warnings issued around noon by Environment Canada.

Nineteen children and two staff were taken to hospital and treated for minor injuries with the most serious injury suffered by a child who needed stitches after being hit in the head by a pole, he said.

That boy is doing fine according to his parents, Doherty said.

Doherty's comments contradict a statement from a spokesperson from Alberta Health Services that one person was sent to hospital in critical condition and two in serious condition.

But Doherty said that report was wrong. Alberta Health Services has declined to comment further on the severity of the injuries.

Every child who was taken to hospital was released by Wednesday afternoon.

Parents arriving at the camp this morning to pick up their children told CBC News they believe staff did a good job in handling the situation.

Doherty said camp officials will assess the condition of the teepees and figure out in coming days what happens next.

Day camps will continue while staff determines if scaled-down versions of the overnight camps are possible, he said.

The camp offers free weeklong camps for children who cannot afford summer camps and day camps for children with physical, mental and emotional challenges.

With files from CBC's Lydia Neufeld