I remember it well as I flew out that morning from Southend on Air Ferry Viscount G-AVHE on a day trip to the Hanover air show with a group of enthusiasts/spotters. On the way back later the same day we got diverted in to Stansted due to the Viscount blocking the runway/overun area. The weather that night was awful and we were thrown about all over the place during the descent and diversion into Stansted-with lightning/heavy rain and severe turbulence followed by the heaviest landing I can ever recall.
The crashed Viscount had apparently aquaplaned and failed to stop within the runway length and overan the runway onto the railway line. (not the first to do so of course). At least that was what we were told on the night!!
We were subsequently coached back to Southend and saw the Viscount on the railway line.