In February 2021, an unidentified attacker remotely accessed the control system of a water treatment plant in Oldsmar, Florida. They attempted to raise the level of sodium hydroxide, a caustic chemical used to balance water pH, to nearly 100 times its safe concentration. The presence of such high levels of sodium hydroxide could have proved lethal had it reached the town's water supply. The attack was not caught by any automated security system. It was noticed only because a plant operator happened to see his computer's mouse cursor moving on its own and reversed the command in time.