Several persons were severely injured in a violent crash Monday morning along state Rt. 33 in Hamilton Township, Monroe County. The crash occurred just after 8 a.m. as a tractor trailer was heading south at the 20 mile marker. The rig apparently swerved to the right, entering the right berm then re-entered the roadway, crossing all four lanes of the highway striking several vehicles head-on. Three medical transport helicopters were used to transport four of the seriously injured to Lehigh Valley area trauma centers. Route 33 was closed from the Lehighton exit to the Wind Gap exit.