The Cincinnati Bengals stadium was an eerie sight during the first quarter of the football game to determine home field advantage in the playoffs. The fans were silent and all the players were out on the field, some comforting each other and some taking a knee. After tackling Bengals wide receiver, Tee Higgens, Damar Hamlin collapsed and experienced cardiac arrest.

It was later assumed that Hamlin suffered from commotio cordis, which is when a blow to the chest causes the heart to enter an arrhythmia or even stop beating. For this to occur, the impact needs to occur at the right moment in the beat of the heart, at the beginning of the T wave.

CPR was administered on the field for nine minutes before Hamlin was taken to the hospital. Medical experts, although unsure of what exactly happened to Hamlin, agree that those nine minutes were crucial in his survival.

“When something like this happens, the heart stops pumping blood, and one of the 100-percent certainties, if resuscitation isn’t done, is automatic death. So it was imperative they responded so quickly.” Says Dr. Aaron Baggish, a team cardiologist for the Patriots and U.S. Soccer. “The real good-news story is how promptly the medical team on the sideline was at his side performing resuscitation. That is not always the case.”

Hamlin was discharged from Buffalo General Medical Center on January 11 and is showing no signs of neurological damage.

“Damar still requires oxygen and is having his heart monitored regularly to ensure there are no setbacks or after effects.” Says Hamlin’s marketing director, Jordan Rooney.