An off-duty Petaluma firefighter helped revive a stricken man at a gym Tuesday afternoon.

The 71-year-old man collapsed shortly after 4 p.m. at Myles Ahead Fitness on Payran Street and was not breathing when the firefighter began CPR, Capt. Martin McCarville said.

On-duty firefighters joined the effort shortly thereafter and were able to restore the man's breathing and pulse by the time he arrived at Petaluma Valley Hospital.

It's not clear what caused the man to collapse, McCarville said. Information on his current condition was not available Tuesday night.

McCarville said Tuesday's incident marked the second time in a month where quick CPR has helped revive someone in Petaluma.

"If people can really focus on that CPR, get their hands on the patient right away and do something," he said. "That's what saves lives."