(CBS) — Dozens of west suburban students may have gone too far by pulling a Homecoming prank on their high school that involved chickens, with damage estimated in the thousands of dollars.

Police are investigating, reports CBS 2’s Chris Martinez.

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It happened at Riverside-Brookfield High School.

Authorities are looking at footage from security cameras all around the school to identify the students who pushed the prank way over the line.

Scraps remained outside the school, the worst of it since scrubbed away.

“I called the police because there was a lot of yelling and screaming outside,” says Melissa Camilleri.

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The prank started simply enough, with toilet paper tossed in trees. But a second, smaller group of students came back later and took it to another level. Photographs of the scene showed a major mess.

“In the morning when I got up I looked and I saw graffiti and chickens!” Camilleri says. “And furniture, like mattresses and a chair and a couch and a crib, I think.”

Alum Steve Marcus saw his share of pranks when he was a student there, but could not believe the estimated cost of damage: more than $3,000.

“In terms of sheer vandalism I guess it is criminal,” he says. “It’s not like just one cherry bomb in a toilet.”

The chickens reportedly were purchased on Craigslist.

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School officials think just over a dozen kids caused the worst of that damage, and as many as 40 took part in the prank. Any number of them could face charges.