KENSINGTON (WPVI) -- Philadelphia police are trying to figure out what caused a chain reaction crash in the city's Kensington section.
It happened around 8 a.m. Saturday near the intersection of Frankford Avenue and Tioga Street.
Police say a US Postal Service tractor-trailer and two cars were involved in the crash.
One of the cars was pushed onto the sidewalk and crashed into a wall.
One person suffered minor injuries from the crash.
It's still not clear who was at fault.
1 person hurt in chain reaction crash in Kensington