Damar Hamlin's heartbeat stopped but was restored after he collapsed on the field mid-game

• Damar Hamlin's heartbeat stopped when he collapsed mid-game on Monday. 
• Hamlin was playing the Cincinnati Bengals on Monday night when he took a hard tackle. 
• His heartbeat was restored but he remains in critical condition, the Buffalo Bills said on Tuesday.

Buffalo Bills safety Damar Hamlin's heartbeat stopped when he collapsed mid-game after a hard tackle on Monday night, per a statement posted on the Buffalo Bills' verified Twitter account at 1:48 a.m. EST on Tuesday. 

"Damar Hamlin suffered a cardiac arrest following a hit in our game versus the Bengals. His heartbeat was restored on the field and he was transferred to the UC Medical Center for further testing and treatment," the Buffalo Bills tweeted.

"He is currently sedated and listed in critical condition," the team added in its statement. 

Hamlin tackled Cincinnati Bengals wide receiver Tee Higgins at 8:55 p.m. during a game on Monday night at the Paycor Stadium. After the tackle, Hamlin got up, staggered away from Higgins, and collapsed onto the field.

Hamlin was given CPR on the field for several minutes. Videos from the scene also showed an ambulance driving onto the field at Paycor Stadium.

Hamlin left the stadium in an ambulance at 9:25 p.m. EST.

The NFL said in a statement posted to Twitter on Monday night that the NFL Players Association agreed on postponing the game.

"Hamlin received immediate medical attention on the field by team and independent medical staff and local paramedics. He was then transported to a local hospital where he is in critical condition," the NFL's statement read. 

"Our thoughts are with Damar and the Buffalo Bills. We will provide more information as it becomes available," the NFL added in its statement.

A representative for the Buffalo Bills did not immediately respond to Insider's request for comment.