Three motorists died yesterday on the A66 following two road accidents.
Cumbria Police have described the accidents as 'tragic'.
"It's absolutely tragic. Four deaths is significant and it'll have a devastating effect on four families. It's unbelievable to happen in one day."
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Early enquiries suggest the men may have taken the drug Blue Valium. Two of them remain in hospital with breathing problems.
More than 8,000 people are expected to attend over the three day event, which starts at 7pm tonight.
The local MP and leader of the Liberal Democrats says it was a "joyful" day for locals and former locals alike.