A leak on a big rig that ran on natural gas led to a fire that caused more than $2 million in damage and losses at a truck maintenance facility in southwest Wichita on Monday, fire officials said. A fire at Fleet Maintenance Inc. in the 3700 block of West 30th Street South caused $1.5 million in damage to the building and $750,000 in losses of building contents, Wichita fire Lt. Jose Ocadiz said Tuesday. Employees were doing mechanical work on a tractor-trailer fueled by compressed natural gas when a gas leak reached a heater inside the building and started the fire, Ocadiz said.