A 7-year-old South Florida boy faces grand theft auto charges after taking his grandmother's Dodge Durango for a joyride on Friday, police said.

The eight-minute trek left a swath of damage in his Palm Beach Gardens neighborhood, during which the boy smashed mailboxes, hit parked cars and signposts. He was unhurt.

Police said he drove until a wheel fell off. The right front wheel broke off after the boy hit a sign.

The boy's mother said he apparently grabbed the keys to his grandmother's sport utility vehicle, backed it out of her driveway, and took off.

Police spokeswoman Ellen Lovejoy said it is unlikely the boy will to be prosecuted. Officials arrested him so he can get some help, noting the excursion was "unusual behavior for a 7-year-old."