WATERVILLE — Police, firefighters and fire marshals determined a slashed truck tire probably was vandalized with a knife Friday morning, after initially suspecting it was flattened by a explosive device.

Police suspected an explosive at first because of the way the hole appeared to have blown out and because of marks on the ground resembling scorch marks, according to Deputy Chief Charles Rumsey.

Rumsey said after running different tests, they determined the pressure from the heavy load the pick-up truck was carrying may have caused the hole in the slashed rear tire to blow out. He said police now are investigating the incident as a simple criminal mischief case.