A teenager was shot and killed by another teen inside the Montbello Recreation Center in northeast Denver Tuesday night, Denver police said.

The shooting took place in the 15000 block of East 53rd Avenue, just south of the Rocky Mountain Arsenal, the Denver Police Department said on social media just after 7 p.m. Thursday. Officers said they found one victim with the extent of injuries initially unknown.

Officials later added to the thread that evening to say that a male juvenile was pronounced dead on the scene. On Friday, police announced that another juvenile had been arrested and faces a first-degree murder charge in connection with the shooting.

The suspect and victim knew each other.

In a statement Friday, Denver Mayor Mike Johnston said he is grieving the teen killed in the shooting. The mayor visited the recreation center Thursday night, according to a news release, and has been in regular contact with Denver’s safety and parks teams.

“No statement can capture the grief we feel today,” Johnston said in the release. “Our hearts are broken. To the family of the victim and the entire Montbello community, know that you have our deepest sympathies and our unwavering support.”

DPD Chief Ron Thomas said the investigation into the shooting is ongoing.

“While the investigation is ongoing, the incident appears isolated as the parties were known to each other,” Thomas said. “We ask the community to keep the victim’s family, loved ones and the entire Montbello community in their thoughts.”

“Every child in Denver deserves the opportunity to grow up free from fear and violence. Anything less is unacceptable,” Al Gardner, executive director of Denver’s Department of Safety, said in the release.

He added that the city will continue to use violence prevention and intervention strategies in attempts to reduce violence. DPD officers and outreach teams are working in the community near the recreation center to support those impacted by the shooting, Gardner said.

Neither the suspect nor the victim has been identified by police. The Denver Gazette requested the arrest affidavit with the minors’ names redacted but the department declined to release it, citing a Colorado law prohibiting police from publicly releasing arrest records concerning juveniles.

A GoFundMe identified the victim in the shooting as Mikail Nasir Khalid Payne, 14. The GoFundMe described Payne as a bright young man with an entrepreneurial spirit who liked helping his parents with their landscaping business.

The Denver Gazette reached out to the family on social media, and through the contact provided on Go Fund Me, but had not heard back as of the publication of this story.

Montbello Recreation Center will be closed until further notice, and all programs at the center have been temporarily canceled.

The Denver Office of Medical Examiner will release the cause and manner of death pending an autopsy. A request for information Friday was not answered.

Anyone with information about the shooting is asked to call Metro Denver Crime Stoppers at (720) 913-7867.