had stopped working; however, the Japan Atomic Power Company stated that there was a second operational pump sustaining the cooling systems, but that two of three diesel generators used to power the cooling system were out of order. Transport Japan's transport network suffered severe disruptions. Many sections of Tōhoku Expressway serving northern Japan were damaged. The expressway did not reopen to general public use until 24 March 2011. All railway services were suspended in Tokyo, with an estimated 20,000 people stranded at major stations across the city. In the hours after the earthquake, some train services were resumed. Most Tokyo area train lines resumed full service by the next day—12 March. Twenty thousand stranded visitors spent the night of 11–12 March inside Tokyo Disneyland. A tsunami flooded Sendai Airport at 15:55 JST, about one hour after the initial quake, causing severe damage. Narita and Haneda Airport both briefly suspended operations after the quake, but suffered little damage and reopened within 24 hours. Eleven airliners bound for Narita were diverted to nearby Yokota Air Base. Various train services around Japan were also canceled, with JR East suspending all services for the rest of the day. Four trains on coastal lines were reported as being out of contact with operators; one, a four-car train on the Senseki Line, was found to have derailed, and its occupants were rescued shortly after 8 am the next morning. Minami-Kesennuma Station on the Kesennuma Line was obliterated save for its platform; 62 of 70 (31 of 35) JR East train lines suffered damage to some degree; in the worst-hit areas, 23 stations on 7 lines were washed away, with damage or loss of track in 680 locations and the 30-km radius around the Fukushima Daiichi nuclear plant unable to be assessed. There were no derailments of Shinkansen bullet train services in and out of Tokyo, but their services were also suspended. The Tokaido Shinkansen resumed limited service late in the day and was back to its normal schedule by the next day, while the Jōetsu and Nagano Shinkansen resumed services late on 12 March. Services on Yamagata Shinkansen resumed with limited numbers of trains on 31 March. Derailments were minimized because of an early warning system that detected the earthquake before it struck. The system automatically stopped all high-speed trains, which minimized the damage. The Tōhoku Shinkansen line was worst hit, with JR East estimating that