Battery Dead problems of the 2006 Dodge Charger

I turned my ignition key to start the vehicle and heard an explosion in the rear of the vehicle. I opened my trunk with the key because the vehicle lost all electrical power. I discovered that the battery had exploded and sprayed battery acid in the trunk area. The trunk was filled with white smoke and smelled like chemicals. My property inside the passenger compartment also had a strong chemical odor to it. After looking at the battery, it appeared to have exploded from the rear and the main thing that kept it from sending acid soaked debris was the nylon strap that holds the battery in place. I am worried that the entire interior of my vehicle is now coated with acid fumes/powder from the explosion. I spoke with huntington beach Dodge and they said I was responsible for all costs of repairs because the battery only has a 12 month/12k mile warranty. I understand that a battery goes dead, but I do not understand a battery exploding! my 2 children were not in the back seat at the time of the explosion, but what could have been the injury to my kids if they were there? battery acid in the face and eyes, acid soaked debris striking them or hearing loss from the explosion? I don't feel comfortable with driving the vehicle or having my children in it. Mcpeek Dodge in anaheim replaced the battery and cleaned the trunk at a cost of $250. 00 (20% discount they said), but stated that they were unable to determine the reason for the incident.