Philip Sullivan, 18, of York County stuck a horse-and-buggy (a sulky type cart) in the 5700 block of Division Highway on Monday at 2:46 a.m., say police.
Andrew Stoltzfus, 18, of Honey Brook, Chester County was ejected from the cart and was transported to Lancaster General Hospital by the New Holland Ambulance Association ambulance.
Stoltzfus suffered multiple injuries.
The horse died at the scene.
Sullivan fled the scene in his 2009 Lexus Sedan.
He was arrested for Driving Under the Influence of Alcohol or Controlled Substance at Main Street near Weaverland Valley Road around 3:20 a.m.
The investigation into this crash is ongoing.
Click here to follow Daily Voice Lower Merion-Narberth and receive free news updates.