By Natasha Lisova.washingtonpost.com. July 17, 2007. A train carrying yellow phosphorus derailed in western Ukraine, releasing a cloud of toxic gas into the air over 14 villages. Twenty people were hospitalized and hundreds evacuated on Tuesday, officials said.Rescuers extinguished a fire that broke out in the highly toxic substance, which can catch fire spontaneously on contact with air at temperatures higher than 104 degrees. It can cause liver damage if consumed. [ See in Spanish ]