Buffalo Bills safety Damar Hamlin was in critical condition at a hospital after collapsing after hitting a single in the first quarter of «Monday Night Football» against the Bengals in Cincinnati, authorities said.

Hamlin, 24, has gone into cardiac arrest, the Bills said in a declaration early tuesday.

«His heart rhythm was restored on the field and he was transferred to the UC Medical Center for further testing and treatment,» the Bills said, referring to the University of Cincinnati Level 1 trauma center. «He is currently sedated and in critical condition.»

Cincinnati led 7-3 when Hamlin tackled Bengals wide receiver Tee Higgins, got to his feet, then fell on his back.

As the coaches surrounded Hamlin, an ambulance arrived on the field. Hamlin received CPR for several minutes, the ESPN announcers calling the game said. Emotional players and coaches stood by, and the Bills got down on their knees to pray.

Family members were with him, the announcers said.

An ambulance leaves the field with Damar Hamlin of the Buffalo Bills at Paycor Stadium in Cincinnati on Monday.Dylan Buell/Getty Images

The NFL said in a statement that Hamlin received immediate medical attention after the incident.

«Our thoughts are with Damar and the Buffalo Bills. We will provide more information as it becomes available,» the NFL said.

The game was suspended and later postponed. Both teams left the field and went to their changing rooms.

The broadcast team at the booth and their colleagues in the network studio were also excited.

MIAMI GARDENS, FLORIDA - SEPTEMBER 25: Damar Hamlin #3 of the Buffalo Bills looks on before a game against the Miami Dolphins at Hard Rock Stadium on September 25, 2022 in Miami Gardens, Florida.
Damar Hamlin of the Buffalo Bills at Hard Rock Stadium in Miami Gardens, Florida on September 25.File Megan Briggs/Getty Images

«Monday Night Football» is an ESPN Production airing on ABC.

The Buffalo Bills tweeted “Bills Mafia is with you, @HamlinIsland”, referring to the player and a name for Bills fans. The Bengals were among the teams that responded with a praying hands emoji.

In a match where players sometimes sustain serious injuries, the apparent severity of the situation was deemed unprecedented on Monday’s broadcast.

The game was suspended with 5:58 left in the first quarter. The NFL officially postponed the contest about an hour later, shortly after 10 p.m. ET.

Buffalo Bills quarterback Josh Allen (17) pauses as Damar Hamlin is examined during the first half of an NFL football game against the Cincinnati Bengals, Monday, Jan. 2, 2023, in cincinnati.
Buffalo Bills quarterback Josh Allen (17) pauses as Damar Hamlin is examined during the first half of the Bills’ game against the Bengals in Cincinnati on Monday.Jeff Dean/AP

The Buffalo Bills tweeted “Bills Mafia is with you, @HamlinIsland”, referring to the player and a name for Bills fans. The Bengals were among the teams that responded with a praying hands emoji. bills quarterback Josh Allen wrote:: “Please, pray for our brother”.

The NFL Players Association, which is the players union, tweeted: “The NFLPA and everyone in our community is praying for Damar Hamlin.

“We have been in contact with the players of the Bills and the Bengals, and with the NFL. The only thing that matters right now is Damar’s health and well-being,» the union said.

After the incident, an «emergency action plan» went into effect, Troy Vincent, the NFL’s executive vice president of Football Operation, said in a conference call later Monday.

Neither the coaches nor the players were talking about resuming play, he said.

«It was really about Demar and making sure that, look, I’ve never seen anything like this since I’ve played,» said Vincent, a former cornerback in the league. He called it a traumatic event.

Hamlin is a native of McKees Rocks, Pennsylvania, which is near Pittsburgh, and was selected in the sixth round of the 2021 NFL draft.

The Pittsburgh Steelers too tweeted, «We send our thoughts and prayers to Damar Hamlin, her family» and the Buffalo Bills.

Bengals fans poured in outside hospital in support, video from NBC affiliate WLWT showed.

“Seeing that on TV didn’t make it any easier,” said Demetria Tutt. “To see that and have children, family members see that, what happened tonight, nobody wants to see that. We’re just praying.»