2000 Audi A4 Car Wont's Start

What would cause my Audi to all of sudden die while I was driving it? After it stopped running I try to turn it over and it acts like the starter is not engaging. I noticed an aluminum pipe thats about 1/2 inch to 3/4 inch in diameter that had been broken in the central passenger side almost directly under tha radiator. There are two of these pipes/tubes that run paralell to eachother running from passenger side to the center. Could these be a type of vacuum tubing that activates the starter or keeps the motor running?
Thank You So Much
Sincerely
Colton Belliston