An investigation is underway into a deadly house fire in Montgomery County. Chopper 3 was over Summit Avenue in Jenkintown where firefighters got to the duplex just after 7:30 p.m. on Friday night. They found a man on the second floor, but he later died at the hospital. The two-alarm fire also sent two firefighters to the hospital, one for a possible heart attack. He’s in stable condition. The other firefighter was released after treatment for heat exhaustion. Several other firefighters suffered minor injuries.