Someone set off a mortar-shell firework inside a Renton man’s vehicle, ruining the vehicle’s interior, according to the Renton Police Department.

The man told police someone set off the firework inside of his vehicle between 6 a.m. Aug. 22 and 11 a.m. Aug. 23 in the 1000 block of North First Street. He had locked the vehicle but had left the right rear window down a few inches.

Police observed powder burns throughout the interior and even residue on the outside of the vehicle. The interior appeared to be ruined; it was covered with pieces of the shell.

The man did not see anyone around his car during that time.