A high school student in Connecticut died after he was severely hurt during a junior varsity ice hockey game on Thursday, officials said, leaving his team and school community reeling from his death.

The injury took place as the 10th-grade student, Teddy Balkind, fell on the rink during a game between two private schools in Fairfield County.

After Mr. Balkind fell, another player was unable to slow down and ran into him. Officials said Mr. Balkind’s neck was cut by the other player’s skate.

The game was immediately stopped and staff members called 911, the police said. Mr. Balkind was treated at the scene before being taken to a hospital but he did not survive surgery, school officials said.

His death spurred waves of shock and grief throughout southwest Connecticut.

The two schools — St. Luke’s School in New Canaan and Brunswick School in Greenwich — mourned what officials called an “unimaginable tragedy.” Local and professional hockey players offered their condolences and shared tributes to Mr. Balkind.

“Our community is mourning,” Mark Davis, the head of school at St. Luke’s, where Mr. Balkind was a student, said in a statement. “We lost a precious young man in a tragic accident. Both St. Luke’s School and Brunswick School are in shock as we work to support our students and families. St. Luke’s singular focus at this moment is to care for our devastated community.”

His hockey program wrote on Twitter that “no words are adequate for the grief we are all feeling.”

The match started around 5 p.m. and gameplay had been “entirely normal and unremarkable” before the accident took place, officials at the Brunswick School said in a letter to alumni.

Mr. Balkind was a longtime ice hockey player, often wearing No. 5 on his jersey and skating for the New Canaan Winter Club. He had attended St. Luke’s, a private institution with grades 5 through 12, since middle school, where he was once recognized for crafting the school’s “artwork of the week.”

Photos on his public Instagram page told a story of a nature- and sports-loving teenager. Videos showed him mountain biking and leaping over branches on trails in Connecticut and Pennsylvania. One image showed him celebrating a state championship with his hockey team.

The most recent photo, posted on Oct. 5, showed him biking through a mountain park. Under it, nearly 1,000 people left comments filled with hearts and messages of “RIP” and “rest easy buddy.”

Mr. Balkind’s family could not be reached for comment on Saturday. School officials said in statements that his father had been in the audience at the game and traveled to the hospital with him.

Clark Jones, the director of hockey at the New Canaan Winter Club, called Mr. Balkind a positive presence on the team and said the community was deeply struggling with the loss.

“We lost a tremendous young man,” Mr. Jones wrote on Twitter on Friday. “Always smiling, a great teammate, and a passionate hockey player.”

St. Luke’s was closed on Friday because of snow but school officials told students the building would be open to offer community members space to process the death.

Officials at the Brunswick School, the all-boys private school and the host of Thursday’s game, said in messages to students that counseling and support services would be in place for the hockey players.

After Mr. Balkind’s death was confirmed in local news reports, families and community members in New Canaan leaned hockey sticks and other sports equipment alongside their door frames and on their porches in his memory.

The news also reached the National Hockey League. Cam Atkinson, a right winger on the Philadelphia Flyers, shared a photo of him participating in the remembrance on social media, writing that he was “heartbroken” for the family. “A horrible tragedy playing the game we all love,” he said.

The league and other teams, including the New York Rangers, also posted messages to Mr. Balkind’s family.

“While it’s hard to put into words the impact of such a loss, know that our thoughts, prayers and hearts are with you,” the Rangers wrote on Twitter.