Heat Tape Mishap (pics and questions)

[zx92027xz]

Sorry the images are so big... but i need help quickly.

i woke up and the tubs were cold, i checked out the tape and it was melted to really badly. i have pics of the wiring, and the tape itself.

(the system ran fine, nonstop, for about 2 months...) then this...

http://www.ball-pythons.net/gallery/...eatTape005.jpg

http://www.ball-pythons.net/gallery/...eatTape003.jpg

http://www.ball-pythons.net/gallery/...eatTape001.jpg

i have 2 more unused levels, so i just have to plug the heat tape into the thermostat and put the snakes in the tubs, but i am hesitant to do so, as i dont want to light anything on fire, or risk the snakes.

additional info...

thermostat set to 91
room temp about 70
heat tape was the only heating element for the rack.
theres almost no seperation between bottom of tub and top of heating element.

id appreciate any help... i just want to know how this happened and what i can do to prevent it from happening again...