A 500-foot perimeter was cordoned off March 23 and more than a half-dozen businesses were evacuated after a private construction crew inadvertently breached a natural gas line on Grand Avenue. Emergency officials said a caller reported hearing hissing sounds and smelling gas shortly before noon outside a fast-food restaurant, triggering responses by police units and the city’s Fire-Rescue Department. The construction crew, which was contracted by the city to replace aging sewer pipes, struck a two-inch-diameter gas main, forcing several neighboring streets to be shut down around the area of Grand Avenue, Hornblend, Lamont, Beryl and Felspar streets. According to San Diego Police Department Lt. Andra Brown, gas smells were detected as far as Olney Street to the east. Maurice Luque, a spokesman for the Fire-Rescue Department, said between six to eight businesses were evacuated as a precaution. No fires or injuries were reported. Repairs to the broken gas line were completed and the area was reopened shortly after 2:30 p.m.