Safety Officials Warn Workers Not to Clear Gas Lines Indoors

Federal safety officials are warning workers around the country not to clear gas lines indoors after a North Carolina factory blast killed three people.

The U.S. Chemical Safety Board said in a safety bulletin to be distributed Friday and obtained by The Associated Press that a June explosion at a Slim Jim snack factory underscored that gas lines being worked on should not be cleared, or purged, indoors.

Investigators believe contractors installing a water heater vented natural gas inside the building, leading to the blast that injured dozens at the plant south of Raleigh, owned by Omaha, Neb.-based ConAgra Foods Inc.

Officials suggested that workers vent gases to a location outdoors and use detectors to monitor gas levels, among other recommen