All but one of the injured inmates, who was treated for smoke inhalation at St. John's Hospital, were taken to the prison infirmary.
The health division is usually for injured and sick inmates.
The injured inmate was escorted to outside hospital for treatment, and the institution was immediately placed on lockdown.
The staff was told to be ready for an emergency to receive a large group of injured inmates.
Correction officials said the other injured inmates were treated at the Rikers infirmary.
The 28 injured inmates were all taken to area hospitals for treatment of smoke inhalation, Mr. Bersin said.
It was only after a week of travelling that the Americans discovered the trains full of dead, injured and starving inmates.
Standard procedure dictates that inmates are to be secured before officers can respond to an injured inmate.
In keeping with the twisted code of prisoners, the injured inmate told the authorities he had been attacked from behind and therefore couldn't identify his attacker.
Pictures were taken on that day, which is standard procedure for injured inmates.