Buffalo Bills safety Damar Hamlin, 24, is in critical condition after collapsing on the field on Monday night during a game against the Cincinnati Bengals. Here’s what we know:

What happened: Moments after getting up from an open field tackle on Bengals wide receiver Tee Higgins, Hamlin fell on his back.

Within 10 seconds, Bills team trainers were treating the player. An ambulance was brought onto the field in under five minutes, footage shows, and Hamlin received CPR, according to an ESPN broadcast. He was then taken to hospital.

Hamlin’s status: The player suffered a cardiac arrest following the hit from the tackle, and his heartbeat was restored on the field, the Bills said in a statement on Twitter early Tuesday.

Hamlin was transferred to the University of Cincinnati Medical Center for further testing and treatment, where he is now sedated, the Bills added.

The game: Play was suspended at 5:58 of the first quarter, then the game was officially postponed. The NFL said more details on next steps would come at an “appropriate time,” adding that Hamlin’s wellbeing was the priority.