A big rig with no driver.
It was enough to get Philly police on the scene and fire and bomb squad crews on alert.
The tractor-trailer was parked in front of the Navy Depot Supply Center in Northeast Philly Thursday morning, left unattended -- that raised a flag of suspicion.
Police showed up at Tabor Avenue and Robbins Street. They checked out the truck's load to rule out any notion of foul play. They found the driver a bit after 8 a.m. and plan to cite him for parking in a spot that's not for 18-wheelers.