Buffalo Bills player Damar Hamlin, 24, reportedly required CPR by NFL health officials on the field during Monday night's game, collapsing after a hit at 8:55.03 p.m. ET in Cincinnati.
Hamlin is in critical condition at University of Cincinnati Medical Center on Monday night.
"His vitals are back to normal and they have put him to sleep to put a breathing tube down his throat," his agent Jordan Rooney tweeted. "They are currently running tests. We will provide updates as we have them."
"I am told that Damar Hamlin has been intubated and is currently listed in critical condition," Fox-19 News anchor Tricia Macke tweeted.
A statement from NFL commissioner Roger Goodell confirmed Hamlin was alive and in critical condition.
By late Monday night, a community toy drive organized by Hamlin had surged to more than $900,000 in donations. His stated goal was $2,500.
Players from both teams were distraught and in tears, while the ESPN broadcast cut away from its coverage. The game was temporarily suspended at 9:17 p.m. ET and postponed at 10 p.m. ET. Reporters noted the Buffalo Bills were flying back home from Cincinnati, putting the game in doubt to be rescheduled.
After being given on-field CPR and an AED, Hamlin was put on a stretcher, given oxygen, and loaded into an ambulance that was driven onto the field.
"I'm told Damar Hamlin has a pulse, but is not breathing on his own," Fox Cincinnati reporter Joe Danneman tweeted. "He is being transported to UC. Needed AED and CPR on the field."
"Ambulance, with police escort, has just left the stadium," he added, with ESPN broadcast noting the ambulance left at 9:25 p.m. ET. "En route to UC."
Hamlin's mother reportedly joined her son in the ambulance.
Hamlin made a tackle on the Bengals' Tee Higgins with 5:58 remaining in the first quarter and after briefly jumping to his feet, fell on his back. Medical staff quickly attended to him while players from both teams took a knee in an emotional scene.
As Hamlin was taken to the hospital players from both teams went to their dressing rooms.
Entering the game, the 6-foot, 200-pound Hamlin had 91 tackles, including 63 solo tackles, and 1½ sacks.
A tweet from the Pitt football account was simple and clear: “Damar Hamlin is the best of us. We love you, 3,” the tweet said, referring to Hamlin by his college jersey number. “Praying for you.”
Hamlin was drafted by the Bills in the sixth round, 212th overall, of the 2021 NFL Draft.
Information from Reuters and The Associated Press was used in this report.