Worst coolant I've ever seen

Looks like a mess I saw a couple weeks ago. We're not sure who, but someone decided to start up a hmmwv and walked away in the middle of doing their PMCS. What step were they in the middle of doing? Apparently, checking the coolant, as they left the cap off the radiator. Someone walked out to the yard and saw coolant spewing up into the air all over the place. Privates..... this is why we can't have nice things in the army!