According to the DA's office, the escort vehicle was pushed into the oncoming lane and sideswiped the bus around 8am, causing the bus to impact one tractor-trailer's load and tip onto its side, prosecutors said.
A Lancaster General Hospital spokesman said three children sustained traumatic injuries. Police are asking the public to call if they find a male driver in a light-colored, newer-model sedan that most likely has front bumper damage. His vehicle will likely have front-bumper damage.
"When you have a situation like this, we set up a special room in our dining area so that families can talk with our counselors, as well as our chaplain to get their answers, if their students are not with them right away", Lines said.
Investigators say four vehicles were involved: a tractor-trailer, an escort vehicle for the tractor-trailer, the hit-and-run vehicle and the school bus.
Police said one student was thrown from the bus and flown to the hospital.
Early Wednesday morning, a vehicle attempted to pass a truck bearing an over-sized load, but ran into its escort vehicle and then spun into the school bus, which was headed to Lancaster Mennonite School.
WHTM reported emergency responders removed one child who was trapped under the bus and airlifted to the hospital.
(Lancaster) - Authorities say a hit-and-run accident resulted in a school bus flipping onto its side sent more than a dozen people to the hospital, including two students with trauma injuries.
Students and a bus driver were hospitalized after a school bus crashed in East Lampeter Township, Pa., May 17, 2017.
East Lampeter Township is about 65 miles west of Philadelphia. The escort vehicle then hit the school bus, which was forced into the mobile home.