The trapped firefighter radioed a “mayday” distress call, after which the firefighters who had just left returned and helped set him free, allowing him to crawl to safety, according to fire inspector Justin Smithmyer.

“Thankfully, they had just exited,” Smithmyer said, when asked what might have happened to the firefighters who’d been in the basement if they hadn’t left before the collapse.

Two people resided in the center house of the three on the 3900 block of Fifth Avenue, but neither were home at the time of the fire — to which firefighters were dispatched at 1:35 a.m., Smithmyer said.

Residents were home in one of the other houses when the fire occurred, Smithmyer said.

An overhead view shows damage from an early morning fire at an Altoona rowhouse along the 3900 block of Fifth Avenue. The fire caused the roof of the center of three houses to collapse onto the second floor. Mirror photo by Patrick Waksmunski

Firefighters found heavy fire in the basement of the center house when they arrived, Smithmyer said.

They commenced an interior attack, but when the first floor collapsed after being weakened by the blaze, they withdrew and proceeded with a defensive approach, Smithmyer said.

The fire also caused the roof of the center house to collapse onto the second floor, Smithmyer said.

In addition to the two individuals who lived in the center house, there were a total of five others who lived in the houses to each side, according to Smithmyer.

The Red Cross was helping them, he said, and most were able to move in with family.

An aerial view shows the rear of a rowhouse destroyed by fire early morning Thursday along the 3900 block of Fifth Avenue. Mirror photo by Patrick Waksmunski

One or two ended up staying in a hotel overnight, he said.

The center house was a rental, while the other two are owner-occupied, he said.

The cause of the fire for now is undetermined, according to Smithmyer.

He was not sure where it started and couldn’t say whether he suspected arson, he said.

He estimated the loss of the center house at between $100,000 and $150,000.

The house to the right from a street perspective received about $50,000 damage, he estimated.

The house to the left received between $10,000 to $15,000 damage, he estimated.

He’s not certain about insurance, he said.

If the houses on each side are insured, it will likely be up to the insurance companies whether they are fixed, Smithmyer said.

Initially, 11 firefighters came to the scene — the full complement of those on duty at the city’s four fire stations at the time, he said.

Six off-duty firefighters were called in after a second alarm.

Firefighters cleared the scene about 7:45 a.m.

Mirror Staff Writer William Kibler is at 814-949-7038.