PEABODY, Mass. -- A firefighter trapped in a smoky apartment fire was rescued by several fire chiefs from surrounding towns on Monday.

NewsCenter 5's Sean Kelly reported that the fire broke out at the Cross Keys Apartment complex on Monday afternoon.

At first, other firefighters thought the 20-year veteran was getting some fresh air near a second-floor window. But they said they soon realized that he needed help.

"At first he appeared like he was just going to get some air, but then it became pretty evident to us that he was in distress," Wakefield Fire Chief Dave Parr said.

Fire chiefs from five departments that responded to the blaze dragged a ladder around the apartment building and hoisted it up to the firefighter at a second-floor window. After tossing his oxygen mask and tank to the ground, the firefighter slid face-first down the ladder away from the thick, black smoke that billowed from the window.

"Basically, we just want to make sure he didn't roll off the ladder as he came out head-first. It looked like he took in quite a bit of smoke, so we quickly ushered him over to the EMS unit," Parr said.

All the 20 residents of the apartment building escaped the blaze safely.

Investigators said they are looking at whether a seal on the firefighter's oxygen mask failed.

"We just happened to be in the right place at the right time. It was a team effort. We saw that he was in distress and we took action. We didn't want him to jump out the window," Parr said.

The name of the firefighter was not released. He was taken to an area hospital to be treated for smoke inhalation.