The carnival, which runs from 4 to 8 p.m. in Mill Park, is in memory of Sylvester Cobbs, a popular community volunteer who died in 2013.

Police said the driver got out to start the truck’s shredding machine when it apparently slipped into gear and moved across the street.

A recent newspaper article about the bedbug situation in the city prompted the anonymous donor to offer his money to help address the problem and prompt others to contribute to do so.

Charles Manning, 74, said he often didn’t sleep at night because he worried about being bitten by bedbugs.