A natural gas explosion on Wednesday, Feb. 9, 2011, devastated Allentown, PA, killing 5 people and destroying an entire city block.

On Wednesday night last week, a massive natural gas explosion destroyed an entire city block in Allentown, PA, and killed five people. Officials looking into the nature of the blast have attributed aging cast iron pipes as one likely cause, according to a story in the Allentown Morning Call.

The story states that, “Not including Wednesday’s blast — the cause of which has not been determined — PUC records show that UGI’s Pennsylvania companies have had 11 gas explosions or serious incidents since 2001, including two other local blasts: in 2003 in Macungie and 2006 in Allentown. The 11 incidents resulted in one injury and more than $3.5 million in property damage.”

It also notes that there are more than 3,000 miles of cast iron natural gas pipes underground in Pennsylvania, and cites a February 2010 PUC report on the natural gas industry that states “these pipes should be replaced with more durable plastic lines. Replacement costs are estimated at $13 billion over 20 years.”

Read the complete story here.