Military vehicles surround a wreckage of a trolleybus, in Volgograd, Russia, Monday, December 30, 2013. A bomb blast tore through a trolleybus in the city of Volgograd on Monday morning, killing at least 10 people a day after a suicide bombing that killed at least 17 at the city's main railway station. Volgograd is about 650 kilometers (400 miles) northeast of Sochi, where the Olympics are to be held. (Photo by Denis Tyrin/AP Photo)

Wu Lingling, a nurse from Central Hospital of Shanghai Fengxian District says goodbye to her husband Zhao Kun before leaving for Wuhan at Shanghai South Railway Station in east China's Shanghai, January 27, 2020. A team comprised of 50 medical workers from 40 hospitals in Shanghai left for Wuhan City on Monday to aid the novel coronavirus control efforts there. (Photo by Ding Ting/Xinhua News AgencyAlamy Live News)

Bangladeshi people climb into the roof of an overcrowded train as they travel to celebrate Eid with family in their villages, at the Kamlapur Railway Station in Dhaka, Bangladesh, 03 June 2019. Muslims around the world are preparing to celebrate Eid al-Fitr, the three-day festival marking the end of the Muslim holy month of Ramadan, Eid al-Fitr is one of the two major holidays in Islam. (Photo by Monirul Alam/EPA/EFE)

People pass a suitcase as they line up to enter a railway station in Beijing, February 15, 2015. Chinese Ministry of Transport said a total of 2.807 billion trips are expected to be made during the 40-day Spring Festival travel rush, which started on February 4 and will last until March 16, Xinhua News Agency reported. (Photo by Reuters/Stringer)

A sign marks a railway crossing next to the troubled Kruemmel nuclear power plant on June 2, 2011 in Geesthacht, Germany. The German government recently announced it will phase out the country's 17 remaining nuclear reactors by 2022 in a policy initiative that represents a radical reversal from its previous policy and was sparked by the disaster at Fukushima. Kruemmel went into operation in 1983 but was taken offline following a fire in 2007. (Photo by Sean Gallup/Getty Images)

An isolated five-floor building stands in the middle of a new road on November 22, 2012 in Wenling, Zhejiang Province of China. Zhejiang Province of China. 67-year-old Luo Baogen and his 65-year-old wife from Xiazhangyang village still live in the half-demolished residential building, because they are dissatisfied with the relocation compensation. The road, which leads to the Wenling Railway Station, has not been put into use. (Photo by China Foto Press)

Three Boeing 737 fuselages lie on an embankment on the Clark Fork River after a BNSF Railway Co train derailed Thursday near Rivulet, Montana in this picture taken July 4, 2014. A train derailment in Montana this week damaged a shipment of jetliner fuselages and other large parts on its way to Boeing Co factories in Washington state from Spirit Aerosystems, Boeing said on Saturday. (Photo by Kyle Massick/Reuters)

Police officers with a sniffer dog check a railway as the Soyuz MS spacecraft for the next International Space Station (ISS) crew of Kate Rubins of the U.S., Anatoly Ivanishin of Russia and Takuya Onishi of Japan is ready to be transported from an assembling hangar to the launchpad ahead of its launch scheduled on July 7, at the Baikonur cosmodrome in Kazakhstan July 4, 2016. (Photo by Shamil Zhumatov/Reuters)