SHERIDAN — A natural gas leak caused a two-block radius near the intersection of Gould and West Burkitt streets to be evacuated Tuesday evening. The incident occurred while crews from Montana-Dakota Utilities were doing routine maintenance on the line.

Sheridan Fire-Rescue Capt. Greg Luhman said buildings in the immediate area of the leak were emptied just after 5 p.m. and tenants were allowed to return approximately four hours later.

“A crew from Montana-Dakota was on site to do maintenance on a pipeline but when they got down to the area where they planned to squeeze off the pipe to stop gas flow to the area that needed maintenance, they ran into an issue while installing the plug, which created the blowing gas,” MDU Spokesperson Mark Hanson said in a written statement to The Sheridan Press.

“The crew then needed to squeeze off the pipe on both sides of that area to stop the flow of gas and make repairs.”

Hanson added that power was shut off to three customers as a safety precaution.

Luhman said MDU called in the incident and that gas flowed until about 10 p.m. because the workers had to wait for repair equipment to arrive from Montana.

“It was pushing hard,” Luhman said, describing the magnitude of the leak. “At one point, the sidewalk was being pushed up by gas pressure. I have never seen that before. As soon as they got the gas clamped, it went back down to a normal level.”

Luhman said two buildings were supplied with natural gas, and his crews worked to clear the buildings. They will revisit key sites today to ensure the threat is gone.

“The nice thing about natural gas is that it’s lighter than air and it dissipates up instead of laying low and traveling down the road,” Luhman said, adding that a strong “rotten egg” smell is added to natural gas for the specific purpose of leak detection.

Hanson said crews will be at the site again today to complete the original maintenance.

SFR was assisted in its response by the Goose Valley Fire Department and Sheridan Police Department.