CCTV footage shows moments before Argentina train crash
23 February 2012 Last updated at 05:26 GMT
Some 49 people have been killed and at least 600 injured in Argentina, after a commuter train crashed as it arrived into one of the busiest stations in Buenos Aires.
The train hit the end of the platform at Once station during the morning rush hour.
CCTV footage shows how the train was unable to stop. The BBC's Tom Esslemont reports.