Hours of the massive collision between the Uttar Banga and Vananchal Express at Sainthia station in Birbhum, Indian Railways spokesperson Anil Saxena said that the exact cause of the accident would be known after a thorough probe into the incident. The toll in the train collision rose to 66 today with three injured passengers of the Vananchal Express succumbing to injuries at the Burdwan Medical College Hospital.