Same in The U.S. as in the U.K. 1. Each driver is required to be in control of their vehicle at all times. 2. Drivers are required to maintain an acceptable distance behind the vehicle in front of you (Usually 1 car length per 10 miles of speed) so as to provide room to stop. So each driver would be partially liable for their own damages and rear end damage to the vehicle in front of them except for the front vehicle who left the scene.
all of them for not paying attention for what they were doing.
In the UK - you should remember that you must travel a safe distance behind the vehicle in front of you. So if the first car had to brake sharply for good reason and the second vehicle hit the first and the third hit the second . . . the second and third driver would be considered At Fault. To see how the highway code helps decide fault for a car accident in the UK - see the link entitled "car accident claim".
