First Capital Connect fined over "litany of mistakes"
16 September 2013 Last updated at 20:42 BST
Train company First Capital Connect has been fined £75,000 after 700 people were stuck between St Pancras and Kentish Town in 2011.
The judge said it was a "shambles" and a "litany of mistakes".
Ian Prosser, office of rail regulation, talks about the investigation while David Statham from the train company says a "wide-ranging" set of initiatives have been put in place to prevent this from happening again.