By 5:30 Monday evening, MSP operations chief Joe Harris realized the day had been like no other in his 30-year career at the airport. Throughout the afternoon, 25 planes destined for O'Hare International in Chicago wound up at MSP instead. "This probably has to rank at the top, or near the top, for number of diversions" sent to MSP in a single day, Harris said. By mid-morning, the MSP Operations Center called in more staffers to handle logistics of the diverted flights. At 1:30 p.m., three hours after MSP's Operations Center started preparing for the diverted flights, the first ones started to arrive.