Lewisham Rail Crash 4th December 1957

At 6.20pm on 4th December 1957 one of the worst rail crashes in Lewisham's and south east London's history took place in dense fog. A passenger train from Charing Cross to Hayes stopped at a signal under a bridge and the following train to Ramsgate crashed into it.  The railway bridge collapsed onto the carriages underneath.  There were 90 fatalities and 109 people were kept in hospital. The trains had been carrying over 2,000 passengers. The bridge had to be cleared away and it was over a week before the lines under the bridge were reopened, and another month before the bridge had been rebuilt and traffic allowed over it.

The driver of the Ramsgate train was charged with manslaughter, but acquitted after two trials. 

You can see a newsreel of the accident on YouTube 

and find out more on Wikipedia