Battery problems of the 1997 Infiniti J30

When I turned the key to start my car that morning the battery blew up. It had enough force that it damaged my hood. When I told my service advisor about it she didn't sound at all suprised. She merely told me that the battery must have gotten too dry. Later I told her that the battery shouldn't have exploded like that even if it was dry. I said I had never known anyone who had a bottery blow up like that, and she said "OH, it happens all the time. " she went on to tell me that they have "about one per week. " this seems extremely dangerous to me because someone could have been severely injured if they had their face anywhere close to that battery when I turned the ignition.