A faulty reptile heating pad caused the fire that shot through the Gatorland amusement park this week, killing three animals and destroying offices, investigators said Wednesday.

Florida Fire Marshall's Detective Bill Newman said the blaze was accidental. He said it was fueled by wood paneling and merchandise in the park's 7,000-square-foot gift shop, where the electrical spark ignited.

"The whole interior of that building and the exterior was covered in wood," he said. "Plus just the gift shop contents itself — T-shirts, sweat shirts."

A crocodile and two pythons kept in pens near the gift shop were killed, but no people were injured.

Newman said the investigation was closed unless samples he sent to a lab came back "off the charts with something."

The three-alarm fire charred the concrete alligator mouth tourists walked through to enter the park — an old Florida icon that has appeared in movies, magazines and countless tourists' pictures.

The fire ruined Gatorland's gift shop and some administrative offices, but did not damage food service or stage areas.

Park officials have set Nov. 22 as a tentative reopening date.

Gatorland is one of central Florida's oldest attractions. It features alligator wrestling shows and exhibitions where visitors can touch and hold reptiles and snakes.