Northwest Iowa Power Cooperative (NIPCO) experienced a transmission‑level outage at 16:45 on May 4 after the NIPCO Control Center was immediately alerted to the event by NIPCO’s internal protection system of any outage on the L3 to Sioux City transmission line. This line includes several electric transmission substations that serve members of North West REC. In response, NIPCO’s electric system operated as designed, automatically opening the line.