A Norfolk Southern Corp. train bound for the Philadelphia area and carrying heavy Canadian crude oil derailed in Vandergrift in Western Pennsylvania on Thursday, the company confirmed.

Twenty-one tank cars came off the track and at least three tank cars leaked crude oil onto the ground, said a Norfolk Southern spokesman. There were no injuries or fire. The thick, heavy petroleum from the Canadian oil sands is not as explosive as the light, volatile North Dakota crude that has been involved in several recent rail accidents that caused explosions.

The train's destination was Morrisville, Pa. The oil tankers involved in the derailment were leased by NuStar Energy and bound for its asphalt plant in Paulsboro, N.J., said NuStar spokeswoman Claire P. Riggs.