420 SEL Just Got Rear Ended and Now it Won't Start

[davestx]

My 1991 Mercedes 420 SEL with 560 motor was hit last night in the rear. The car ran after the accident and I was able to pull it over to the side of the road. After sitting for a while sorting out the accident information, I tried to restart the car. It ran briefly and then cut out. I tried to restart it a number of times and it would briefly start for a second and then die. I had to have it towed because the battery started to run down. I can hear the fuel pump running when I turn the key. Any thoughts as to what could cause this? Thanks.