Around 200 passengers were trapped in a crowded underground train for two hours in Vienna yesterday (Tues).The U4 line train got stuck in a tunnel between Schottenring and Roßauer Lände stations between 2pm and 4pm after a power cut.According to Viennese public transport agency Wiener Liniens error management guidelines, a stranded train must be evacuated within 15 minutes.”We regret the incident and would like to apologise to call affected customers,” Answer Lang, a spokesman for the company said today.Lang stressed that the firm has started to investigate over the “mistake in company-internal communication” which forced the 200 passengers to remain in the underground train for around two hours.The Wiener Linien official refused to say whether the firm is considering offering the passengers financial compensation.Barbara H. told the Kurier newspaper that two men forcefully opened one of the doors but passengers were not allowed to leave the U-Bahn train on their own initiative.The 22-year-old revealed that an announcement informed the people inside the U-Bahn of a “technical breakdown” soon after the train came to a sudden standstill in the dark before an hour with no information whatsoever followed.The student also told the Viennese daily that the heating stopped working after some time.The stuck underground was eventually hauled out of the tunnel by a diesel-powered engine.Yesterdays incident may increase the public pressure on Wiener Linien.Only last week, a short circuit sparked a small fire in a train on the U4 line in a tunnel. The wagon quickly filled with smoke, but none of its dozens of passengers were injured.A few days earlier, it emerged that a passenger left lying in a “Nightline” bus by the driver at the end of his shift was found dead the next morning.Wiener Linien was criticised for not publically reporting the incident itself. The story was uncovered by Viennese newspapers around one week later.Some reports claimed it is common practice among drivers to let possibly drunk passengers sleep it off after parking the bus in the garage. “We usually leave the doors open after parking the buses. They are normally all gone in the morning,” a driver was quoted as saying.Wiener Linien reacted to the reports by stressing that the driver who left the 40-year-old man, who was found dead by a cleaner, inside the vehicle was immediately suspended. He may face criminal charges if forensic experts find that the person was still alive while the bus was in operation.