A sudden flash of 1,000-degree heat at a house fire Thursday claimed the life of a veteran San Francisco firefighter who was trapped with his colleagues in the hillside home.
Lt. Vincent Perez, 48, died trying to extinguish a fire at the four-story home in Diamond Heights. He was caught in a "flashover" - an unexpected explosion caused when temperatures rise so high the contents of a room spontaneously ignite, Fire Department spokeswoman Mindy Talmadge said.
A second firefighter, 53-year-old Anthony Valerio, who is also a paramedic, was in critical condition late Thursday at San Francisco General Hospital with severe burns.
A third firefighter was treated and released for minor burns and smoke inhalation, Talmadge said. Her name was not released.
"The Fire Department is like a family, and we lost a family member today," Fire Chief Joanne Hayes-White said. "It's a tough day in San Francisco."
The cause of the fire is still being determined, and "a lengthy investigation" is likely, Talmadge said.
Children ran screaming
Perez and Valerio were among 30 firefighters who responded to the fire at 133 Berkeley Way around 10:45 a.m. A woman who was in the home and three children escaped the flames, the children screaming, "Fire! Fire!" as they ran from the house, said Patty Stanton, a neighbor who was walking her dog nearby.
"It got really chaotic and scary really quickly," she said.
Firefighters' first indication that their colleagues were in trouble came when one of the victims apparently hit an emergency button on his radio that triggers an alarm at the dispatch center.
The dispatcher then tried to contact the firefighter directly to confirm the button hadn't been hit accidentally.
"They didn't get a response," Talmadge said.
The dispatcher then radioed the incident commander on the scene, who launched a "rapid intervention operation," a crew dedicated to helping firefighters in trouble, Talmadge said.
Two were unconscious
All three firefighters were found together. Perez and Valerio were unconscious, and the third firefighter was able to walk out on her own, officials said.
Stanton described firefighters giving CPR to two of their colleagues after pulling them out of the house.
Police homicide inspectors arrived on the scene of the fire at 1:05 p.m., which Talmadge said was standard procedure in blazes with serious injuries.
Perez was a San Francisco firefighter for 21 years. He was born and raised in the Mission District and Bernal Heights, and was known for his courage and sense of humor, said Tom O'Connor, head of the firefighters union.
"He was always the first guy in a fire and the last guy out," O'Connor said. "He lightened up the mood at the firehouse. ... He was a firefighter's firefighter."
The flag flew at half-staff in front of Fire Station 26 in Diamond Heights, where a station crew member said two of the three firefighters were based.
Colleagues distraught
A group of colleagues sat in the station's common area, slumped in chairs, some with eyes red and swollen from tears. They referred all questions to headquarters.
"We're just grieving right now," said one firefighter who declined to give his name.
Shortly after 4 p.m., Perez's body was wheeled from the hospital to a medical examiner's vehicle between two lines of saluting firefighters and several police officers, some of them in tears. One of Perez's brothers is a San Francisco police officer and another is an Oakland police officer.
One of his brothers, who was crying, helped medical technicians wheel Perez's body, wrapped in an American flag, into the vehicle. Mayor Ed Lee, O'Connor and several police officers stood in silent salute alongside the firefighters.
Lee ordered all flags to be hung at half-staff.
"This is a devastating day for our city, and I join all of San Francisco in expressing our deepest gratitude and profound sorrow for the loss one of our own," Lee said. "Our hearts are heavy as we are reminded of the sacrifices firefighters and their families make each day to keep our city safe."
Officials said it was the first time a San Francisco firefighter had died in the line of duty since January 2003, when Melinda Ohler fell from a moving fire engine while responding to an alarm at San Francisco International Airport.
The last time a San Francisco firefighter died in a fire was in 1995, in the same neighborhood as Thursday's tragedy. Lt. Louis Mambretti, 57, was killed when an automatic garage door slammed shut and trapped him inside a burning home in Diamond Heights.
Deceptive appearance
From the street, the house that burned Thursday appears to be two stories, but has two additional stories built into the slope of a hill in the back. Talmadge said such structures "historically have caused us problems."
Firefighters rushing into such buildings often do not realize that they're on the ground floor or grasp the layout, she said.
"Flashovers" are a well-known firefighting hazard.
"When you're in there, you can't see anything," Talmadge said. "There is extreme heat just prior to the flash."
Temperatures during a flashover can reach 1,000 degrees, said Scott Kouns, a spokesman for the San Jose Fire Department.
The opposite of a back-draft, a flashover occurs when the temperature in a room rises so high - 400 degrees or hotter - that its contents ignite, driving the temperature even higher. In a back-draft, the temperature rise occurs without oxygen; in a flashover, super-heated oxygen is what causes the combustion.
Taken by surprise
Typically, firefighters will break windows, cut holes in walls and the ceiling and take other steps to ventilate a room and lower the temperature before entering. But in some circumstances, depending on the contents of a room, the height of the ceiling and other factors, a flashover can occur suddenly, Kouns said.
"A flashover is definitely something you look for when you go into a fire. It's always on your mind," Kouns said. "Sometimes you go into a fire and it seems straightforward, but then things change very fast. Our hearts go out to these guys' families and crew members."
