The fire at Columbia Middle School in Logansport was reported about 2 a.m. Monday. No injuries were reported, but the school was closed for the day.
Assistant Fire Chief Mike Wollington says firefighters were able contain the blaze to the classroom, although much the school had smoke damage.
Fire investigator Ted Franklin says the heat lamp for a snake terrarium had been plugged into a series of three extension cords that weren't rated for such a heavy electrical load. He estimated the fire burned for five hours before it triggered an alarm.