Four people, including three firefighters, were injured in a fire early Tuesday in the city's Marshall-Shadeland neighborhood.

A fire bureau Go Team -- firefighters on standby at the scene to help trapped colleagues -- rescued two of their own who were trapped inside the structure.

A 15-year-old boy who lived in the residence is credited with saving his father and elderly aunt.

Pittsburgh firefighters responded to the scene around 1:15 a.m. The fire was in a section of row houses in the 3100 block of Shadeland Avenue.

By then, 15-year-old Wayne Parker Jr. had dragged his father away from trying to extinguish the blaze, then he and a neighbor ran back inside to rescue his 83-year-old aunt.

The three-alarm fire destroyed the row house owned by the Parkers.

The adjacent apartment, which was vacant, also sustained some fire damage. Firefighters stopped the blaze before it spread to the other two abandoned units in the row.

Two firefighters, working their way into the basement of the second unit, fell and were injured when the stairs collapsed.

The two, whose names were not released, were being treated for minor injuries, fire officials said. One was treated and released at Allegheny General Hospital, and the second remained hospitalized, fire Chief Darryl Jones said.

A third firefighter suffered minor injuries, the chief said.

Wayne Parker Sr., 54, was being treated in the burn unit at UPMC Mercy. He suffered second-degree burns of the hands, arms, back and chest, his son said.

Wayne Jr. said he smelled smoke around 1 a.m. and immediately checked on his aunt, Angelina Loos, who had been sleeping on the first floor.

Unable to find the fire extinguisher, Wayne Jr. said he ran to check on his father, whom he found standing in a bedroom amid flames trying to put out the fire with the extinguisher.

Wayne Sr. uses an oxygen tank to assist his breathing.

"He was on fire. It was pretty bad," Wayne Jr. said.

After the father and son evacuated, Wayne Jr. headed back inside for his aunt. Another teen happened by and ran inside with him, the teen said.

The two boys helped Ms. Loos to safety.

Wayne Jr. said the family, which had no homeowners' insurance, lost everything.

Lyn Huber and Eileen McCurrach, who live across Shadeland Avenue from the Parkers, called 911 after the sound of the oxygen tank explosion jolted them.

The two women and their daughter, Kayla, 8, took in Wayne Jr., Ms. Loos, and their 11-year-old pet dog, Gizzy.

The neighbors said the Red Cross will assist Ms. Loos and the Parkers, but the family is unclear about their future.

The fire caused about $110,000 in damage, fire officials said.

Fire investigators said the blaze was started when Wayne Sr., who had been smoking in bed, put out the cigarette on a dresser or night stand where some clothing ignited.

Wayne Jr. and his father were on their way out of the house when they heard the first explosion from the oxygen tank. He and neighbors said there were more explosions after that.

Chief Jones credited the Go Team with operating as it was designed.

He said that a Mayday call "sets off a chain of events that alerts the Go Team."

"Fortunately, they were not hurt seriously and they weren't unconscious. They were able to help themselves a great deal."

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