An employee dispute at an Arvada Big O Tires escalated into a shooting that left one person seriously injured yesterday afternoon, creating a scene of disrupted lives and customer inconvenience at the 7425 W 52nd Avenue location, local authorities and witnesses report. The Arvada Police Department said that an argument between two employees turned physical in the service area before one employee drew a firearm and shot the other in the torso, as reported by Denver7.