ORLANDO, Fla.- The Orlando hospitals that treated dozens of people injured in the Pulse nightclub massacre are not billing survivors for out-of-pocket medical expenses.

News outlets report Orlando Regional Medical Center, which treated most of the survivors of the June 12 attack, announced Wednesday that it would seek payment from other resources such as insurance plans and a victims' fund established by city officials.

Florida Hospital, which treated 12 survivors, says it would not bill for any of its services.

Officials say the two hospitals will write off an estimated $5.5 million or more in care.

The attack killed 49 people and injured more than 50 others, making it the deadliest mass shooting in modern U.S. history. The gunman, Omar Mateen, was killed by police after a three-hour standoff.