dr. abid kamal is a expert in the investigation of fires and explosions. >> there's a collapse of the roof. a lot of the three-dimensional objects because more or less two-dimension a. in the met afterwatt the investigation becomes more challenging. that's when atf and other investigators uses a tool like this up, a thermal imaging camera. >> it picks up signals of heat and can you use that to map out an area and see which areas are still warm as opposed to that gone comb. here's what regular imaction look like. the cup on the table is red because it's filled well hot kevy. in a fire the -- you may know that you need to remove the sheetrock to look no that area with a camera like that. >> so anything that's warm or hot is emitting energy in the infrared spectrum? you can't see it with the naked eye, but you can with a thunderstormal imaging camera. vic lee, abc 7 news. >>> well, the tragedy in oakland is prompting the fire departments across the country to look at similar buildings that could be dangerous n.baltimore, inspectors ender the bell foundry arts building this week to investigate