It wouldn't surprise me if the battery exploding caused it. They can explode, and that surely is not any vehicle manufacturers fault. Did you get any warranty from the dealer you got it at?
I know you said the van had no power brakes or steering, but was running, both of which would have been there IF the van was running, I'm assuming that the engine was off already. The power steering runs of the accessory drive and the power brakes are assisted by engine vacuum that is present while the engine is running. Regardless I'm sure it was a panicing situation for sure. Please keep us posted. Best of luck
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