Arizona safety inspectors are lending their expertise in Massachusetts, where pipeline explosions last month killed one person and injured several others.
The Arizona Corporation Commission says two inspectors from their pipeline safety section began restoration work Monday in Merrimack Valley.
The two men will help crews inspect pipeline through Nov. 24.
Authorities say a series of explosions on Sept. 13 decimated homes and left 11,000 households without gas service.
Investigators found the cause was excessive pressure in natural gas lines.
Crews are still working to replace nearly 45 miles (72 kilometers) of mainline gas pipes and more than 6,000 service lines connecting residences and business.
Gas service is still shut off for a majority of the area.