Parents and kids in a popular children's group woke up to a rude surprise Sunday morning -- while they were sleeping over at Science World, someone keyed nearly every car in the parking lot.

The side panels and doors of some 70-80 cars in the parking lot were wrecked -- a disappointing ending to a great weekend out with the Beavers, parents said.

"Every vehicle in the parking lot has been keyed, front to back, every side panel, every door," said Rob Williams, who slept over Saturday night with his son. "It's frustrating."

The Beavers are a group of kids between five and seven years of age, and many Beavers go on to become Cubs and then Scouts as part of Scouts Canada.

Several chapters from Kelowna and the Okanagan -- meaning some 250 kids -- had stayed over at Science World as part of a group event. Science World officials were shocked that the vandalism had taken place.

"This is not a normal experience," said Suan Teo, the director of marketing for Science World.

Initial reports had pegged the number of cars that were vandalized at about 200. But Teo said by mid-afternoon Science World had compiled a list of incident reports from parents, and only as many as 80 cars were reported vandalized.

Teo said Science World had regular patrols inside its building while the kids were inside, but no security guards were patrolling the parking lot that night.

Guards do patrol the lot during the day at peak season, she said.

A line-up of parents filled out police reports before they left Science World Sunday morning.

Over Easter, as many as 100 cars near Austin Avenue in Coquitlam had their paint jobs damaged. That same month in Burnaby, about 75 cars were keyed, and in early March, nearly 300 cars in Coquitlam were hit in similar acts of vandalism.

Vancouver police Const. Tim Fanning told CTV News Sunday morning that it was too early to say if the vandalism near Science World was related to the other events. Officers would have to compile the reports and then search for photo or video evidence, he said.

"What a senseless crime," said Fanning.

"We'll have to get our car repainted," said another parent, Bill Schatz. He estimated that it would cost $1,000 to get his car repainted.

Still, he said, he wouldn't let this dampen his spirits.

"Things like this can be repaired," he said. "I had a great weekend with the kids."