The Bills said Hamlin’s "heartbeat was restored on the field and he was transferred to the UC Medical Center for further testing and treatment."
As of Tuesday, he remains hospitalized in critical condition.
The scary incident occurred with 5:58 remaining in the first quarter and Cincinnati leading the game, 7-3. The Bengals were on their second drive of the game when quarterback Joe Burrow threw a pass to Tee Higgins. Bills safety Hamlin came over to make a tackle to end the play.
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Hamlin was on the ground for a while as he received CPR from the medical staff on the ground before he was put into the ambulance. Hamlin was being rushed to the University of Cincinnati Medical Center.
The NFL later announced it postponed the game between the Bills and Bengals. The league also announced Tuesday that the game between the Bills and Bengals would "not be resumed this week" and that no decision has been made "regarding the possible resumption of the game at a later date."
"The NFL continues to be in regular contact with the medical team caring for Damar Hamlin, and also the Bills and Bengals organizations and the NFL Players Association," the statement read.
"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 league said in a statement.
Hamlin’s family released a statement on Tuesday expressing "sincere gratitude" for the outpouring of support they received amid a "challenging time" for the family. They also thanked the more than 150,000 fans that have donated nearly $4 million to his charity toy drive fund.
"On behalf of our family, we want to express our sincere gratitude for the love and support shown to Damar during this challenging time. We are deeply moved by the prayers, kind words, and donations from fans around the country," the statement read.
"The NFL has been in constant communication with the NFL Players Association which is in agreement with postponing the game."
The NFL Players Association also released a statement on the matter.
"The NFLPA and everyone in our community is praying for Damar Hamlin. We have been in touch with Bills and Bengals players, and with the NFL," the NFLPA said in a tweet. "The only thing that matters at this moment is Damar’s health and well being."
NFL executive Troy Vincent said in a conference call with reporters he "never seen anything like it" and he played several years in the league.
The Bills selected Hamlin with the No. 212 overall pick in the sixth round of the 2021 draft. He played in 14 games last season – mostly on special teams – in his rookie season.
Hamlin, 24, was playing his 16th game of the season. He had seen more time on the field as he recorded 91 tackles and 1.5 sacks.