Four people were taken to hospital following a four-vehicle collision on Tampines Expressway (TPE) on Saturday (Nov 7).A video posted on Facebook page SG Road Vigilante shows three ambulances and a police car at the scene of the accident, as well as a man on a stretcher being wheeled towards an ambulance.In responds to AsiaOne's queries, the police said they were alerted to the accident on TPE towards the PIE at about 4.45pm on Saturday.Two male…