The Texas Rangers or some other outside agency could be asked to investigate what may have been the deliberate sabotage of automated treatment plant systems that led to the water crisis in Marlin, the town's city manager, Kenneth Knight, said Tuesday. A formal investigation has not yet been launched, but Knight said in a written report that long-term maintenance failures and the disabling of automated treatment plant systems led to the crisis that left homes, businesses, schools, two prisons and the county jail in Marlin without service for a week.