Rochester, MN – Minnesota Energy Resources continued to dig holes Thursday to release natural gas trapped in the frozen ground in a southwest Rochester neighborhood where it is believed a natural gas leak caused an explosion and devastating house fire.

Families that were evacuated from 11 homes in the area of Ninth Avenue and 36th Street Southwest will not be able to go home until Minnesota Energy crews are done releasing the gas.

Minnesota energy shut off gas to 15 homes, and Rochester Public Utilities shut off electricity to 100 homes. All but seven houses now have electricity, said Tony Benson, RPU spokesman. RPU turned the power back on about 8:30 p.m. Wednesday at the request of Minnesota Energy and the Rochester Fire Department, Benson said.

By mid-afternoon Wednesday, Minnesota Energy found the underground pipe that was leaking. It was fixed, but the company continues to investigate what caused the problem, said police Sgt. Jon Turk, the city’s emergency management coordinator. It could be related to shifting ground caused by freezing and thawing, but that is only a theory, said Ann Carlon, a Minnesota Energy external relations manager.

The explosion occurred in a house at 823 36th St. S.W. about 3:30 a.m. Wednesday. The ensuing fire destroyed the house, but the occupants — Robert Welchlin, his fiancee, Elizabeth Beach, and Alex Laumann, who rents a room in the house — all escaped with only minor injuries. A neighbor said Welchlin’s dog also escaped.

Natural gas leaking and spreading underground caused authorities to evacuate the area. Some families spent the day and much of the evening at Zumbro Lutheran Church, where the Southeast Chapter of the American Red Cross set up a shelter. Other families went to work and school for the day.

Wednesday night, the evacuees stayed in hotels booked by Minnesota Energy. The three occupants of the house that burned down stayed in a hotel courtesy of the Red Cross, said Colette Gallagher, Red Cross communications and development coordinator.

Rochester Fire Battalion Chief Steve Belau said that at the peak of the fire Wednesday, he had 22 firefighters on the scene. That included off-duty crews who came in to help.

Many Rochester police officers also were on the scene, blocking off access to the area and keeping it secure while the evacuated homes were opened for ventilation.