were killed in a recirculation pit (sump) by asphyxiation from argon inerting gas used to support welding on stainless steel piping. July 13, 1990 one person was killed by electrocution and three others suffered severe burn injuries from a 4kv switchgear explosion. In September, 1997, both units were shut down for approximately three years when, as a result of NRC inspections in the engineering area, it became unclear whether emergency core cooling systems could perform their intended functions in the event of a design basis accident. In 1998 the NRC imposed a $500,000 civil penalty for 37 regulatory violations, mostly concerning the containment ice condenser used in responding to some loss-of-coolant accidents. On May 12, 2002, Unit 2 was automatically shut down due to the failure of both redundant DC power supplies in the Reactor Control & Instrumentation System. Due to inadequate corrective actions, the same event occurred on February 5, 2003. A transformer fire caused an automatic shutdown of Unit 1 in 2003 and release of cooling oil to Lake Michigan. A massive intrusion of fish caused both units to be manually shut down for several weeks on April 24, 2003. Due to the degradation in Essential Service Water flow to the plants' Emergency Diesel Generators, the site entered the Emergency Plan at the Alert level. The Alert was exited approximately 25 hours later. On September 20, 2008 unit 1's main turbine and generator were damaged by severe turbine vibrations caused by broken low-pressure turbine blades. A fire also broke out in the generator of Unit 1. No radiation was released and Unit 2 continued to operate at full power. The plant's Unit 2 reactor was shut on October 12, 2020. American Electric Power Company Inc. said service was suspended from the 1,168 megawatt (MW) unit when it tripped due to lowering water level in one of the plant’s four steam generators. In the late night hours of June 22, 2021, operators discovered a leak in a high pressure steam line providing non-radioactive steam to the low pressure turbines of unit 2. The leak appeared to grow larger as it was monitored, leading to a manual shutdown of unit 2. A plant spokesman stated that an assessment is underway to determine the cause of the steam leak and develop a repair timeline, however, I&M does not release return-to-service projection information for generation units for competitive reasons. Meanwhile, unit 1