Photo taken on May 17, 2013 shows a train at Bridgeport station, a station near the scene of the train collision, in Connecticut, the United States. Two trains collided after one of them derailed during the Friday evening rush hour in Fairfield, the US state of Connecticut, injuring at least 60 people. (Xinhua/Wang Lei)

Emergency workers arrive the scene of a train collision, May 17, 2013 in Fairfield, Conn. A New York-area commuter railroad says two trains have collided in Connecticut. (Source: AP)

Photo taken on May 17, 2013 shows a carriage of a train at Bridgeport station, a station near the scene of the train collision, in Connecticut, the United States. Two trains collided after one of them derailed during the Friday evening rush hour in Fairfield, the US state of Connecticut, injuring at least 60 people. (Xinhua/Wang Lei)

Photo taken on May 17, 2013 shows a train near the scene of the train collision, in Connecticut, the United States. Two trains collided after one of them derailed during the Friday evening rush hour in Fairfield, the US state of Connecticut, injuring at least 60 people. (Xinhua/Wang Lei)

Photo taken on May 17, 2013 shows a train at Bridgeport station, a station near the scene of the train collision, in Connecticut, the United States. Two trains collided after one of them derailed during the Friday evening rush hour in Fairfield, the US state of Connecticut, injuring at least 60 people. (Xinhua/Wang Lei)

Photo taken on May 17, 2013 shows a train near the scene of the train collision, in Connecticut, the United States. Two trains collided after one of them derailed during the Friday evening rush hour in Fairfield, the US state of Connecticut, injuring at least 60 people. (Xinhua/Wang Lei)