Semi overturns on I-76 EB ramp to Route 100 in Uwchlan Twp., Chester CountyA tractor trailer packed with Amazon products flipped onto its side in Chester County Tuesday. A tractor trailer packed with Amazon products flipped onto its side in Chester County Tuesday. A tractor trailer packed with Amazon products flipped onto its side in Chester County Tuesday. A tractor trailer packed with Amazon products flipped onto its side in Chester County Tuesday. UWCHLAN TWP., Pa. (WPVI) -- A tractor-trailer packed with Amazon products flipped onto its side in Chester County Tuesday.