ANDOVER, Minn. - Anoka County authorities are searching for the person or persons responsible for setting a series of fires at parks, one of which destroyed a playground.

Authorities say they are investigating six unsolved fires in three different Andover parks. The most extensive damage occurred in Shadowbrook Park. The arson took place about a week ago causing $50,000 in damage.

"It's just a terrible thing that happened here," said Chris Mayers, who comes to the park regularly with his wife and kids. "It's hard to explain to a kid why somebody would do this."

According to the Andover Fire Department, the arsons began about two months ago with burned trash bins. The six fires now include dumpsters and portable toilets. In addition to Shadowbrook Park, fires were also discovered at Purple Park and Sunshine Park, the largest in the city.

"We know from past practice that small fires turn into big fires and we don't want that to happen" said Andover Fire Chief Jerry Streich. "It's really a crime against people, and from a fire chiefs perspective it puts my firefighters at risk just simply responding to these but it also puts fear in the community."

"I even question, you know, is it an arsonist in the making that could eventually hurt somebody?" Mayers said. "They should be ashamed of their actions."

The Anoka County Sheriff's Office has added surveillance cameras and extra patrols at several city parks. They are also working with local schools to spread the word about the crimes and search for suspects.

An award of up to $5,000 is being offered for information leading to an arrest. Call the Anoka County Sheriff's Office at (763) 427-1212 or submit a tip anonymously through the Anoka County Sheriff's Office website.