damn man that sucks...but 99% of the time in those situations the one in back (or in second if more than two are involved) will be considered at fault, reasoning being they were too close to the car in front of them to stop on time. the only way the person in front will be at fault is if their tail lights arent working...and the only way you can tell that is to try them...and 85% of the time the tails are damaged anyway and you're considered at fault.

btw the past tense of 'damage' is 'damaged'.