well, I actually wasn't home for it...but from what I surmised from the wreckage, The heater overheated, exploded, and broke one of the light bulbs, which started an electrical fire and cracked the tank itself, leaking 10 gallons of water from the second floor into my little brothers room, onto his bed waking him up...it was 3AM, he yelled and my dad woke up, though the tank had leaked, walked into the room where the tank was expecting water and he found a fire covering half the room...lucky he had a gas mask handy and was able to get into the room with a fire extinguisher and a gas mask and put out the fire...if he hadn't either the fire would have consumed the entire room, or the seams on the 55 gallon tank right next to it would have gone and hopefully put out the fire...needless to say I now do not use glass tube heaters...I got this phone call while in college at 3 AM that I had to drive home and clean up the fire and water damage right then...not a fun phone call. I found my lobster in the tank, covered in fire extinguisher goo, cooked to a perfect pink, and that is how my lobster tank caught on fire.