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How Firefighters Figure Out What Causes Chicago's Biggest Fires

By Ariel Cheung | June 2, 2016 6:23am
 Two cigarette fires in Lakeview have the Chicago Fire Department contemplating how to spread the word on fire prevention.
Cigarette Fires in Lakeview
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LAKEVIEW — No good deed goes unpunished, but rarely do you get this kind of catastrophic blowback.

For Earth Day, the residents of 1065 W. Cornelia Ave. gathered up cigarette butts littering Lakeview gutters.

Those who smoked added more used cigarettes to the heap over the next month, stashing them in a plastic bin on their back porch.

But one cigarette didn't go out. Instead, it smoldered for hours, heating the rest of the discarded cigarettes refuse until they caught fire.

Paper ignites at 451 degrees Fahrenheit. The plastic bin starts melting at just 200.

The deck went next, and "once that happens, you've built yourself a nice little bonfire," said Capt. Michael Murphy, who investigated the Cornelia fire just days after another discarded cigarette sparked a three-alarm fire at 3338 N. Marshfield Ave.

A back porch in Lakeview, where a discarded cigarette sparked a large fire in May. [Provided/Chicago Fire Department]

The two fires displaced 38 Lakeview residents in a single week — a freak occurrence in a neighborhood where fires usually involve city trash bins or, at their worst, garages.

Murphy has sleuthed for the Chicago Fire Department for 12 years, with another eight as a firefighter. As head of fire investigations, he oversees the roughly 1,200 cases that merit investigation of about 3,000 fires that burn across Chicago each year.

So far in 2016, the department has investigated 448 fires. About half have been ruled accidental, meaning human action (intentional or not) did not play a part in starting the fire.

The number of fires in Chicago has not changed significantly over the past decade, Murphy said. Figuring out how to better educate the public on fire prevention could change that.

"Smoke detectors are an early alert system that says, 'There is a fire,'" Murphy said. "We need to go beyond the smoke detector and realize what prevention can be done before we even get to the smoke detector."

There are a couple common mistakes Murphy wants to stamp out: overusing temporary extension cords or Christmas lights beyond 90 days, for example. Stringing together multiple extension cords or leaving them wedged under furniture can also spark electrical fires.

Discarding smoking materials is another big issue — while there isn't a statistical increase in Chicago fires caused by cigarettes, they're an easy item to mishandle, Murphy said.

A fire at 3338 N. Marshfield Ave. ravaged multiple buildings and displaced 30 people. [DNAinfo/Ariel Cheung]

"You have to be mindful that everything you have in your home in some way or form is dangerous," he said. "We just have to be a little bit more cautious about what we do."

Nationally, smoking caused just 2 percent of residential fires in 2013, according to the most recent data from the U.S. Fire Administration. Cooking started about half of the 380,300 residential fires in 2013, while heating and electrical malfunctions were responsible for another 20 percent.

Over the past decade, fires in the U.S. have decreased by 21 percent, with 1,240,000 fires in 2013 dropping from 2004 by about 310,500.

But smoking-related fires are deadlier than average, causing 13 percent of fatal residential building fires. Other common causes of fatal residential fires are careless or unintentional acts (17 percent), arson (11 percent) and electrical malfunction (10 percent).

Completely extinguishing a cigarette butt is crucial, Murphy said. Smokers should suffocate the stubs in sand or a flowerless dirt pot. A bucket with water is also fine, as long as it gets refilled.

Putting butts in plastic cans or bags, particularly those filled with greasy kitchen waste, is a huge "don't," Murphy said. Chicago is notorious for garbage chute fires in high-rise buildings, the long fall re-igniting the cigarette.

Investigators determined a discarded cigarette sparked a huge fire at 3338 N. Marshfield Ave. in May. [DNAinfo/Ariel Cheung]

Still, fires are fairly rare, with an average of eight fires per day across the city.

Fatal fires are quite even more uncommon — the United States sees about one death in every 380 fires — but smoke inhalation can poison a victim's blood with carbon monoxide. A few deep breaths of smoke can kill.

"Plenty of people die and are never touched by fire," Murphy said.

Out of the 33 fire fatalities in Chicago last year, only four involved people who burned to death. Two of those were ruled homicides, Murphy said.

Investigators are automatically called to fires in large commercial buildings, building collapses, multiple structure fires and any fire with reports of someone trapped inside. If even an odor of smoke is reported in public buildings like hospitals or theaters, investigators also respond.

Once the fire is extinguished, investigators search for its point of origin. Burn patterns shaped like inverted cones or in a "V" each tell a story and help determine where a fire began. Generally, it's in the area most damaged by the fire, which doubles every 30 seconds as it spreads:

Ideally, the "process of elimination" directs investigators to a small section of a room, with residents filling in the final details of what sort of combustible material was available, Murphy said.

"The area of origin is always science-based, and sometimes there's a little bit of a guess, depending on the level of information available," he said. If a structure is reduced to rubble, there's not much evidence left.

There are four main reasons fires start: electrical issues, natural acts, open flame and human action. Chicago's red "X" buildings, for example, don't have running electricity or gas, so "you automatically know it's human action of some kind," Murphy said. 

The interviews are key; investigators suspended the case of an April fire in Lakeview where two people were critically injured jumping to safety. Another pair were rescued from the bedroom where the fire began, but are still intubated and unable to speak with investigators.

As such, that fire investigation is considered "suspended" until authorities can discuss what materials were at the point of origin.

"We have a really good idea where it started but we can't eliminate something until we get more information," Murphy said.

Sometimes, the results aren't what investigators expect. Oily rags used to apply floor stain spontaneously combusted and burned down a Woodlawn church last year. Lithium ion batteries in iPhones and other electronic devices can overheat while charging, particularly when they're stuffed under a pillow or mattress.

Murphy recalled one curious fire caught on surveillance video at a Victoria's Secret Downtown. Investigators initially thought someone intentionally set fire to a mannequin's clothing, until they watched the video.

The footage shows a light malfunction catching fire and igniting a plastic banner. As it burned, the flames heated metal insulation that dropped a glob of molten steel. The steel sustained heat at 1,200 degrees for about 20 minutes, setting fire to the mannequin clothes.

"It's actually not that easy to start a fire," he said. "It takes a lot to get something going, the right conditions. But the ability is there, just tempting fate."

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