17 children, 1 adult injured after walkway collapses during school trip to Fort Gibraltar in Winnipeg

Eighteen people, 17 of them children, were taken to hospital after many of them fell about five metres from an elevated walkway at Fort Gibraltar in Winnipeg's St. Boniface area on Wednesday.

Jason Shaw, a Winnipeg Fire Paramedic Service assistant chief, said the accident happened shortly before 10 a.m. He said three of the children were taken to hospital in unstable condition, while the remaining patients were in stable condition.

The children are 10- and 11-year-olds from St. John's-Ravenscourt School who were on a field trip, the school confirmed in a statement.

Tameem Aljafari, 10, said he was among three classes of Grade 5 students who were on the field trip. He estimated about 30 people were on a walkway at the site when it fell.

"Randomly, it just started cracking when we were on it, and then a lot of people just fell down," he told reporters outside Winnipeg's Children's Hospital.

WATCH | Aerial camera shows collapsed walkway at Fort Gibraltar:

A teacher and two students were under the walkway when it collapsed, he said.

"I just didn't know what happened and then I couldn't breathe."

Aljafari received scratches, but said the people who were under the walkway were more seriously injured.

Health Sciences Centre was put into code orange, which is triggered by disaster events that result in a mass influx of patients, said Dr. Karen Gripp, medical director of the Children's Hospital emergency department.

"As of right now, there is one patient being admitted to hospital for observation. The rest either have been or will be discharged today," Gripp told reporters outside the hospital on Wednesday.

"It could have been so, so much worse. We were prepared for the worst."

Adult and pediatric surgeons, orthopedic surgeons and medicine and trauma staff were called on for help, which caused some surgical delays, she said.

"I don't think it overall had a huge impact, but there was definitely a period of time where everything was on hold just to make sure we knew what we were dealing with."

WATCH | No life-threatening injuries, ER director says:

The majority of the injuries were orthopedic-related and none were severe or life-threatening, Gripp said. One injured boy will remain in hospital to receive orthopedic surgery for a fracture, but is expected to be discharged shortly afterwards.

Some children fell directly from the walkway at Fort Gilbraltar, but others slipped down, she said.

There were 28 people assessed at the scene, and those who needed hospitalization were out of the building within an hour, according to paramedic operations platoon chief Michelle Bessas.

She said the walkway is about five to five-and-a-half metres (almost 20 feet) tall.

The cause of the elevated walkway's collapse is currently unknown but provincial and city workers will inspect the structure, the city told CBC News in an email. The walkway was last repaired in 2013.

Fort Gibraltar is a 1978 replica of two earlier forts of the same name. The original fort was used as a centre for fur trade commerce and early settlers in Winnipeg, according to its website.

The North West Company built the original fort in 1810 and it was captured and destroyed by the Selkirk Colony in 1816. The historic site is now owned by the city but managed by Festival du Voyageur, who told CBC News the children were there for a tour of the building.

Festival du Voyageur is co-operating with the appropriate authorities and Fort Gibraltar is expected to be closed indefinitely, Chantal Vielfaure, Festival's director of marketing, communications and sales, said in a statement.

Archana Paul, whose 10-year-old son was on the field trip, first learned about the incident through a group chat for moms whose children attend St. John's-Ravenscourt school.

"I knew right away that something was not right," said Paul who rushed to the hospital and discovered that her son wasn't there and had likely returned to the school.

"I was just worried about all the kids," she said. "It's just so heartbreaking."

Winnipeg Mayor Scott Gillingham said in a tweet that his thoughts are with the injured and their families.