My first exposure to fire was joining a volunteer fire department when I was 16. My father signed me up. He said, 'I made you a member. Do anything about it if you want to.' I did volunteer firefighting until I was in my late-20s. My first degree is in civil engineering from Cornell, and for two of the three years I was there, I lived in a firehouse. It's a free room, except when the bell rings, you go.
One day, I recognized that you could put engineering and fire together. I looked into it more, and, next thing you know, I wasn't a civil engineer anymore! I finished the degree and then went to the fire protection program at University of Maryland.
Fire protection engineers are trained in how fires start, how they grow, how we protect buildings against fires, how fire departments are part of protection schemes—so anything from how do you get people out of buildings to how do you decide where to put smoke alarms?
Many fire protection engineers never get to actually deal with fires at all. They sit in an office and design a sprinkler system. Other parts of fire engineering, where you're involved with research or fire investigation or understanding flammability of materials, there's actually lab work where burning things is involved. We do both here.
Fires start lots of different ways, but however they start, they obey the same laws of physics. They all involve ignition, flame spread, development of the fire, formation of a hot smoke layer in the room, and movement of the smoke through the building. This is broadly called fire dynamics.
How you determine where a fire started is a combination of physical evidence and eyewitness testimony. You will, after the fire, be able to examine the damage to assess where it burned the longest. It is generally the case—though not always the case—that the fire burns longer at the origin of the fire than it does other places. Within those areas you can have burn patterns that are indicative of where the fire had burned, how it may have spread. You have information from building systems, alarm systems, and from people who discovered the fire. There's usually some form of electrical evidence where you could see shorting on wires, which could be the cause of a fire, but could also be the result of a fire, so it's not always that straightforward.
In terms of forensics, I do a lot of fire investigations. I do it everywhere. I may actually do less in Maryland than I do other places. I had no involvement in the two December five-alarm fires in Baltimore. Private investigators undoubtedly were involved because there were insurance policies involved. That could have been me, but it was not, in this case. There are fires that I go out of my way to understand, but these weren't extraordinary enough to make me want to go looking for them. Because in the general scheme, yes, I see enough of fires, thank you very much.
Most of the work that I do in fire investigations is civil-litigation based. The single most common kind of fire case is one insurance company suing another insurance company. Of course, there are situations where people are injured or die as a result of a fire. Then there can also be criminal investigations.
There is such a thing as spontaneous combustion. The prototypical examples of that are big piles of coal or wood, hay piles, things of that sort. These materials, sometimes biologically, sometimes chemically, produce small amounts of heat. Because they are in big piles, the heat can't be dissipated. So, it will heat up inside the pile, and, at some point, it will start smoldering—and you may not be able to tell that that's happening. Then the smolder will reach the surface of the pile, and then it will typically transition into a flame, and then everybody knows.
I have not personally come across a pyromaniac. But people have psychological problems that lead them to cause fires, there's no question about that. There's some human behavior in fire that we understand and some that we don't.
People talk about panic in fires. There's very little panic in fire, really. Most of the time, what people think of as being panic behavior is people doing very rational things based on what they know. After the fire, we can see everything that happened. What they had was very partial information and they usually act rationally based on the information they do have.
People don't always recognize how quickly fires can grow. You can go from fire in a wastebasket to a whole room burning in three or four minutes. That's why we try to educate people to immediately respond to alarms because there's not much time.