When firefighters from the San Francisco Fire Department's Station 8 see a construction site these days, they see more than a framework slowly taking shape as an apartment house or office building.

Now, a year after the Station 8 crew was among the first to rush to the scene of a blaze that destroyed a six-story apartment building under construction in Mission Bay, the firefighters see the potential for another inferno.

Pat Rabbitt, a Station 8 lieutenant, says he and fellow firefighters size up the new buildings they see with the Mission Bay fire in mind.

“We’re noticing similar construction,” Rabbitt says. “We’re trying to figure out other ways to go about it should we ever encounter the situation again.”

"The situation" Rabbitt's referring to is the blaze that raced through the sprawling wood-frame structure at Fourth and China Basin streets -- just across the way from AT&T Park -- last March 11. The fire caused $40 million in damage and injured several firefighters. It ranks as one of the most destructive fires in the city since the 1989 Loma Prieta earthquake and the worst construction blaze in the Bay Area since San Jose's Santana Row fire in 2002, which destroyed a large section of the mixed residential-commercial development and caused $130 million in damage.

Rabbitt, two other firefighters and the commander who directed the battle against the blaze sat down recently to recount the challenges of that day a year ago and to talk about what they learned.

The first call about the fire came in at 4:57 p.m. on a Tuesday afternoon. Rabbitt was at Station 8, at Bluxome and Fourth streets, just eight short blocks from the 172-unit building under construction.

When Truck 8 firefighters Tom Murphy and Stephen Maguire arrived, the incident did not seem that serious. The two men climbed an aerial ladder to the top of the building.

The assumption was they'd make an "interior attack" to extinguish a blaze, maybe a trash fire, inside the structure or on the roof. That assumption didn't last for long.

"We had a rapid change in conditions," Rabbitt says.

“We’re at the top of the ladder and we’re stepping off the ladder onto the scaffold when things erupted,” Maguire recalls. “When we were at the top floor, I looked in and saw the entire upper floor was on fire.”

Assistant Chief Matthew McNaughton was the man in charge on the ground.

“I could tell this was a rapidly evolving fire, consuming tons of fuel in open construction, which had no passive or active fire protection features,” McNaughton says. He could see a ball of fire developing between the third and fourth floor and thought Murphy would be killed.

McNaughton decided to get his men down from the aerial ladder and fight the fire defensively -- setting up aerial ladder pipes around the building to hit the fire with heavy streams of water.

“We had to make a rapid change,” McNaughton says. “I knew their lives were in absolute peril. I made an immediate decision there to change the tactics of this fire.”

He ordered Maguire, Murphy and others off the building’s roof, but not before Murphy sustained second-degree burns to his face. Murphy, injured, continued to battle the fire for hours.

“That was a big game so you’re not going to leave with a charley horse,” Murphy said. “You’re going to stick it out and get taken care of at the end.”

That moment when the firefighting tactics changed still bothers Truck 8 firefighter Maguire.

“We had a small window to make an aggressive fire attack on that building and that window closed pretty quickly,” Maguire says. “You know, this fire, we’re kind of embarrassed to talk about it a little bit because it got so out of hand,” he said. “That’s not the way we want it to go.”

There were concerns the fire would spread. Embers from the blaze landed on the roof of a building down Fourth Street on the UC San Francisco campus. Windows in an apartment building across the street began to blow out from the intense heat.

Those fears dissipated when firefighters extinguished the nearby small blazes. It took hours for firefighters to contain the fire.

Investigators later determined that the March 11, 2014, fire was accidental, most likely caused by welding or grinding on the building’s top floor. The city fined a subcontractor and implemented stricter safety rules governing construction work at a time when San Francisco is in the midst of a building boom. City and state inspection and safety agencies have been on a hiring spree, adding more staff to keep up with the surge in development.

According to Suffolk Construction, the main contractor on the building, demolition at the site began three days after the fire was extinguished. Ever since then, crews have been rebuilding. The company says tenants will begin moving into the building in June, a year later than originally planned.