During a routine inspection Thursday morning, high levels of gas were detected prompting the closure of roads near the intersection of Northern Avenue and Hardy Road.
Workers from Heath Consultants, a subcontractor for Southwest Gas, detected gas in two manholes at 7:55 a.m. The workers then contacted Southwest Gas, according to Oro Valley Police Sergeant Matt Horetski.
The gas company called Golder Ranch Fire District and the Oro Valley Police Department, who decided to close the roads as a precaution.
Two nearby houses and churches were evacuated. The intersection and surrounding roads were closed to all pedestrian and vehicle traffic.
Once the leak was found, which was located at a transition line where one line connects to another, Southwest Gas closed off the main valves surrounding the leak. About six customers were temporarily without gas service.
Southwest Gas spokeswoman Libby Howell said inspections are ongoing throughout locations the company services. She said leaks, which are usually small, are common.
"The system worked the way it was suppose to work," Howell said. "We did the inspection and we found the problem before it could have been worse."
Roads were reopened at about 10:10 a.m.