On June 9, 1994, a 2-inch-diameter steel gas service line that had been exposed during excavation separated at a compression coupling about 5 feet from the wall of a retirement home in Allentown, Pennsylvania. The escaping gas flowed underground, passed through openings in the building foundation, migrated to other floors, and exploded. The accident resulted in 1 fatality, 66 injuries, and more than $5 million in property damage.