Rookie firefighter Brendan K. Cawley's first real-life bout with the dangers of the job caught him by surprise, he told a Bronx jury yesterday.

Cawley was on the fourth floor of the Tremont building on that January 2005 morning - just a month after graduating from the city fire academy. He said he was huddled near a bedroom window with Lt. Curtis Meyran and firefighter Eugene Stolowski, waiting to be rescued when the black smoke swirling behind them gave way to punishing heat.

"There was just a big boom of heat that hit us ... a tidal wave that came down on us," said Cawley, 35, of Flushing. "I remember thinking that the right side of my face felt like it was burning off of my head when that heat hit us. I have never felt anything like that."

Cawley, who was on his knees removing his empty air pack, said he remembered leaping to a window where Meyran and Stolowski were refilling with air. "I had to get my head out that window," Cawley said. "I was just burning. If [Meyran] wasn't there I would have ended up out that window."

Those three along with three fellow other firefighters ultimately jumped 50 feet to the ground in a desperate attempt to save their lives. Meyran, 46, of Malverne, and firefighter John Bellew, 37, of Pearl River, died in the blaze. Cawley and Stolowski spent months in the hospital.

Cawley is the third of four firefighters who jumped and survived to testify in the three-week-old manslaughter trial. It is not clear whether Stolowski will take the stand.