NIPAWIN, Saskatchewan — A semi-trailer slammed into a bus carrying a youth hockey team in western Canada, killing 15 people and injuring 14 in a catastrophic collision that a doctor compared to an airstrike and left the vehicles obliterated in the snow. The crash sent shockwaves of grief through the team’s small hometown and a country united by the national sport.

Canadians were moved to tears on Saturday as they learned of the identities of the deceased on the bus that was driving the Humboldt Broncos hockey team to a crucial playoff game Friday against the Nipawin Hawks.

“An entire country is in shock and mourning,” Prime Minister Justin Trudeau said. “This is every parent’s worst nightmare. No one should ever have to see their child leave to play the sport they love and never come back.”

The bus had 29 passengers, including the driver, when it crashed at about 5 p.m. on Highway 35, police said. Among the dead are Broncos head coach Darcy Haugan, team captain Logan Schatz and radio announcer Tyler Bieber. Authorities earlier said three were in critical condition but later provided an update to say that 15 have now died.

I want to recount something Mayor Muench said. When he learned about the crash he showed up to the rink. There were people sitting in the stands just staring at the empty ice surface. That was the place the people of Humboldt gravitated to in their time of need. The hockey rink.

— Charles Hamilton (@_chamilton) April 7, 2018

Canadian police said the truck driver was initially detained but has since been released and provided with mental health assistance. Royal Canadian Mounted Police Assistant Commissioner Curtis Zablocki said it’s too early to state a cause for the crash.

In a tweet, U.S. President Trump said he called Trudeau to offer his condolences to the families of victims.

The WHL is shocked & deeply saddened by the devastating news of the tragic bus accident involving members of the Humboldt Broncos.

We extend our heartfelt condolences to the Humboldt Broncos, the SJHL & the families impacted.#HumboldtStrong | https://t.co/fDhShrODDf pic.twitter.com/tKkJtitlBB

— The WHL (@TheWHL) April 7, 2018

Darren Opp, president of the Nipawin Hawks, who the Broncos were set to play against, said a semi T-boned the players’ bus — an account police confirmed.

“It’s a horrible accident, my God,” Opp said.

Hassan Masri, an emergency room doctor at Saskatoon’s Royal University Hospital who has done work in war-torn Syria, said the crash reminded him of an airstrike.

Photographs of the wreckage showed the twisted trailer with most of its wheels in the air and the bus on its side and its back portion destroyed. The force of the crash sent both vehicles into the ditch at the northwest corner of the intersection.

Aerial footage showed the bus on its side, its roof peeled back and its front end destroyed. The trailer of the truck lay nearby in a shattered mess, with bags of its peat moss cargo scattered all around. The tractor part of the truck was intact, lying on its passenger side.

Our deepest condolences to the @HumboldtBroncos community. The hockey world is here for you.

— Black Bear Hockey (@MaineIceHockey) April 7, 2018

The tractor-trailer would have had to yield to a stop sign before crossing over the highway that the hockey bus was travelling on. There is a stand of trees on the southeast corner of the intersection, limiting visibility of the approach on both roads.

Police said a lot of issues have to be investigated, including weather conditions at the time and any mechanical issues with the vehicles.

A memorial at the stairs that lead to Elgar Petersen Arena is shown in Humboldt, Saskatchewan, on Saturday. Police say there were 28 people, including the driver, on board the Humboldt Broncos bus when it crashed with a tractor-trailer around 5 p.m. Friday on Highway 35 north of Tisdale.

The tragedy brought to mind an accident in 1986, when the Swift Current Broncos team bus slid off an icy highway and crashed in late December, killing four players.

The Humboldt Broncos are a close-knit team from the small city of Humboldt, Saskatchewan, which has a population of about 6,000. Many gathered at the community center at the hockey arena there after word of the horrific crash began to circulate.

Humboldt Mayor Rob Muench, wearing a green and yellow Broncos team jersey, hugged people Saturday morning as they came to the Elger Petersen Arena in the Saskatchewan town to comfort each other and learn more.

“It’s overwhelming. It’s been tough on everybody,” Muench said in a phone interview. “We’re a small community; some of those kids have been on the team for a number of years. A lot grew up in the community and everybody knows each other.”

Our hearts are heavy this morning. The Boston Bruins send our thoughts and deepest condolences to the Humboldt Broncos, their families, and the entire Humboldt community.

The hockey world is with you during this difficult time.

— Boston Bruins (@NHLBruins) April 7, 2018

The team was on its way to play in Game 5 of a semi-final against the Nipawin Hawks.

“Hockey was what brought us all together and we had two communities that were rivals in the rink. To find out that it was their first responders that aided our boys just warms your heart,” the mayor said as his voice cracked.

Multiple crisis workers were assisting relatives and friends.

“Everybody is just so devastated. These poor young boys,” said Penny Lee, the communications manager for the town of Humboldt.

The Saskatchewan Junior Hockey League is a junior ‘A’ hockey league under Hockey Canada, which is part of the Canadian Junior Hockey League. It’s open to North American-born players between the ages of 16 and 20.

Team President Kevin Garinger said parents from across western Canada were struggling to cope with the tragedy and were rushing to the scene.

“We are heartbroken and completely devastated,” Garinger said. “We will never forget the members of our Broncos family who were taken from us and who were injured.”

Michelle Straschnitzki, who lives in Airdrie, Alberta, said her 18-year old son Ryan was transported to a hospital in Saskatoon, Saskatchewan.

“We talked to him, but he said he couldn’t feel his lower extremities so I don’t know what’s going on,” she said. “I am freaking out. I am so sad for all of the teammates and I am losing my mind.”

Kevin Henry, a coach who runs a hockey school in Prince Albert, Saskatchewan, said he knows players on the team.

“This is I would think one of the darkest days in the history of Saskatchewan, especially because hockey is so ingrained in how we grow up here,” he said.

The hockey world issued messages of condolences, including Saskatchewan native Mike Babcock, who is the Toronto Maple Leafs coach.

Babcock, fighting back tears, said that “it’s got to rip the heart out of your chest.”

The Chicago Blackhawks and Winnipeg Jets wore the name “BRONCOS” instead of their nameplates on Saturday night.

Rob Gillies contributed to this report from Toronto and Ivan Moreno contributed from Milwaukee.