550 injured in Buenos Aires train derailment One car penetrated nearly 20 feet (six metres) into the next, Argentina's transportation secretary, JP Schiavi told reporters at the station. Passengers said windows exploded as the tops of train cars separated from their floors. The trains are usually packed with people standing between the seats, and many were thrown into each other and to the floor by the force of the crash. This machine left the shop yesterday and the brakes worked well. From what we know, it braked without problems at previous stations. At this point I don't want to speculate about the causes," Ruben Sobrero, union chief on the Sarmiento line, told Radio La Red. The motorman has been hospitalized and the union hasn't been able to speak with him yet, Mr Sobrero added. Local television pictures showed a trapped train driver and several people being carried away from the scene on stretchers. The accident occurred just five months after another major transit incident rocked the Argentine capital, during a morning rush hour crash involving two trains and a bus. That accident in September killed 11 people including the bus driver and injured more 200. The region's transit system has been plagued with serious accidents in recent years. In March 2008, 18 people were killed and 47 injured when a bus was hit by a train in Dolores, 132 miles south of Buenos Aires. Argentina's deadliest train tragedy was in 1970, an accident that killed 200 people in northern Buenos Aires.