Melvin was in critical but stable condition Sunday night in the burn unit at Temple University Hospital. Ayers said he was alert and talking to his family and "doing well."
Bill Gault, president of Local 22 of the firefighters' union, said Melvin was burned on both arms and his back.
Two other Engine 27 members, identified by Ayers as Francis Dougherty and Matt Johnston, were treated at Hahnemann and released.
Ayers said Sunday night that he did not have identities of the residents who were hurt, but he said they were alerted to the fire at 5:58 a.m. by a smoke alarm.
Firefighters, whom Ayers said arrived at the scene within three minutes, explored the house looking for anyone still inside. The three who were hurt found themselves above the fire when they got to the third floor. They became trapped.
Dougherty and Johnston were able to make it down a fire-truck ladder, Ayers said. Melvin stayed back until his men were clear, then tried to get out through a window and onto the ladder. He fell to the ground.
Ayers said the origin of the fire was uncertain Sunday night, but he said there was suspicion of arson.
Contact staff writer Tom Infield at 610-313-8205 or tinfield@phillynews.com.