People try to board a goverment bus during the second day of a suspension of public transport services in Apopa, El Salvador July 28, 2015. Violent gangs in El Salvador ordered bus drivers to strike on Monday in a conflict that has killed six people and left thousands of commuters stranded on the streets of the Central American capital, police and bus company officials said. (Photo by Jose Cabezas/Reuters)

This aerial photo shows the wreckage of the Asiana Flight 214 airplane after it crashed at the San Francisco International Airport in San Francisco, Saturday, July 6, 2013. (Photo by Marcio Jose Sanchez/AP Photo)

Playboy founder Hugh Hefner (not pictured) arrives at Stansted Airport on June 2, 2011 in Stansted, England. The photograph is a recreation of a picture originally taken in the 1960's, with ten of the new London Bunnies. Mr Hefner is back in the UK to mark the launch of the new Playboy Club in Mayfair, which opens on June 4. The clubs opening will welcome back the iconic Playboy Bunny to Londonafter a 30 year absence. Famous Bunnies have included Debbie Harry and Lauren Hutton. (Photo by Dan Kitwood/Getty Images)

Tens of thousands of vehicles damaged by super storm Sandy are being temporarily stored on runways and taxiways at Calverton Executive Airpark in Calverton, New York, on January 9, 2013 in this aerial view. Insurance Auto Auctions Inc, a salvage auto auction company specializing in total-loss vehicles, acquired the cars and trucks that were damaged, destroyed or flooded by the storm and needed a place to store them. The company made a deal with the Town of Riverhead to lease the airport land and then the vehicles are auctioned online. (Photo by Stan Honda/AFP Photo)

People look through the front windshield of a damaged trolleybus in Donetsk, January 22, 2015. At least seven civilians were killed on Thursday when a shell or a mortar hit a trolleybus stop in the rebel-controlled city of Donetsk in eastern Ukraine, a Reuters witness said. The Reuters cameraman said he saw six bodies on the ground near, and inside, a trolleybus in a southern district of the city. Windows of shops nearby had been blown out by the blast. (Photo by Alexander Ermochenko/Reuters)

In this Tuesday, August 2, 2016 photo released by Xinhua News Agency, people stand on a platform as the Transit Elevated Bus TEB-1 conducting a test run after it unveiled in Qinhuangdao, north China's Hebei Province. The 72-feet long and 25-feet wide Transit Elevated Bus (TEB) powered by electricity can carry more than hundreds passengers, is designed to go over the normal traffic to help ease traffic congestion without having to dig new tunnels or build elevated rail tracks. (Photo by Luo Xiaoguang/Xinhua via AP Photo)

A screen shows the new Automated Target Recognition software as a TSA employee, who couldn't provide her name, waits to walk into the advanced imaging technology unit to demostrate the new software that has been installed at Miami International Airport on August 23, 2011 in Miami, Florida. The new software is designed to enhance passenger privacy by eliminating passenger-specific images and instead auto-detecting potential threat items and indicating their location on a screen which shows a generic outline of a person. (Photo by Joe Raedle/Getty Images)

A worker fills a public bus with diesel as the bus driver and passengers look on, at a fuel station in Kolkata, India, February 1, 2017. (Photo by Rupak De Chowdhuri/Reuters)