A National Football League employee was seriously injured in a shooting Monday at a midtown Manhattan building that houses the NFL's offices and some of the country's top financial firms, commissioner Roger Goodell said in a memo to employees.
Four people, including an off-duty New York City police officer, were killed and another person was critically wounded in the shooting at 345 Park Ave., authorities said.
"One of our employees was seriously injured in this attack. He is currently in the hospital and in stable condition," Goodell wrote in the memo, which was obtained by ESPN. "NFL staff are at the hospital and we are supporting his family. We believe that all of our employees are otherwise safe and accounted for, and the building has nearly been cleared."
Goodell said in the memo that there would be "increased security presence" at the league's offices "in the days and weeks to come." He said employees based in New York should work remotely Tuesday or could take the day off.
"Every one of you is a valued member of the NFL family," Goodell wrote. "We will get through this together."
Police identified the gunman as Shane Tamura, of Las Vegas, and said he killed himself. He had a "documented mental health history," but the motive was still unknown, Police Commissioner Jessica Tisch said at a news conference.
"We are working to understand why he targeted this particular location," Tisch said.
Tamura had a three-page note with him claiming that he suffered from CTE and asking that his brain be studied, police sources told ABC News on Tuesday. References to the NFL in that note were vague, sources told ABC.
CTE, or chronic traumatic encephalopathy, can only be diagnosed through a brain autopsy. It is a degenerative brain disease linked to repeated blows to the head.
The New York City Fire Department said emergency crews were called to the Park Avenue office building around 6:30 p.m. for a report of someone shot.
NFL employees were told to shelter in place at the time, ESPN's Jeff Darlington reported. The NFL offices are on floors five through eight of the 44-story building.
Four others sustained minor injuries while attempting to flee.
New York City Mayor Eric Adams said officials are still "unraveling" what took place.
The Associated Press contributed to this report.