Damar Hamlin, a player for the National Football League’s Buffalo Bills, was in critical condition late Monday after collapsing on the field after making a tackle.

Hamlin initially got back to his feet, but then fell back to the ground. Medical personnel administered CPR on the field before sending Hamlin in an ambulance to a local hospital.

Players from Bills and the opposing Cincinnati Bengals were visibly shaken and gathered together in prayer.

The league later announced the game had been postponed.

Some information for this report came from The Associated Press and Reuters.