On February 9, 2011, a natural gas pipeline exploded under a row of brick houses in Allentown, Pennsylvania. Five people were killed, including a four month old baby boy. As many as sixty additional people were injured. Two row homes were flattened, others were set on fire; 47 buildings were damaged.

The pipeline was owned by UGI Utilities, Inc. A 12 inch cast iron pipe system, it was installed 83 years earlier.