I have to say I'm a bit puzzled by the scaredy-cat reaction to the UPS situation and lack of prep.
Knowing there were lead acid batteries involved, why was this not opened up OUTSIDE? The biggest danger would have been the venting of chlorine and possibly flammable hydrogen, which although it goes bang is loud and scary rather than dangerous in the amounts a battery can usually put out into a leaky casing like a UPS (not hermetically sealed usually - mask me how I know this), but you don't want either happening inside.
Knowing there were lead acid batteries involved, why no large pack of Baking Soda on hand? Useful for spills and preventing splashes turning into burns. Also good for stopping spilt acid from being acid. And quenching fires too.
Knowing there were corrosive chemicals involved, why no bucket of water for emergency immersive washing? Yes, water can make things worse (like with lion battery mishaps) but with lead acid jobs large amounts of water are a skin's best friend. Also good four pouring on acid spills to take the bite out of 'em. Also to stop the acid splashes from taking the paint off the director's Jag.
And most of all, why no big metal box for dropping the whole thing in until it stopped fizzing, sparking and doing it's worst? Outside this would simply be a possible cause of a phone call from the neighbors to the police/fire brigade if it all went smoky and blazey, but the important thing is it would be outside, not in the office basement.
Reminds me of the time a neighbour called the fire brigade to tell them his entertainment centre (a 1970s compact hifi thingy) was smoking. They arrived in Dennis, their fire engine, and the neighbour said "it's okay, I just unplugged it and it stopped smoking."
Two firemen, bit between their teeth and adrenaline-crazed from the drive over from the fire station elbowed him out of the way, grabbed the entertainment centre, carried it out onto the front lawn and chopped it to matchwood with their shiny axes to the amusement of onlookers.
Don't call the fire brigade if you don't mean it. They take their work seriously and love to chop stuff to bits. I mean, who wouldn't? I would if I were a fireman. It's half the fun and most of the point.