Read on to the last paragraph, I think what they meant to hint at is this:
> And about those WWII bombing raids? Midway through our work, we noticed a demolition team carefully dismantling a live 500-pound Allied bomb just 350 feet from our location. According to a local office worker, this wasn’t unusual; numerous unexploded bombs had been found on-site in the years prior, prompting evacuations in 2004.
If you live in Europe, there's a reasonable chance you've had the experience of being (or living) in the proximity of an uncovered leftover WW2 bomb at some point that needed to be defused. Because those bombs didn't all disappear in the 40s.
I'm guessing in this case that could've meant somebody could've found that entire hangar and its contents and just cleaned the "junk" out entirely.
little anecdot. I have a garden in my hometown in germany and the garden was only so cheap because it is impossible to build on it because it has wayyyy to many WWII Bombs underneath and its not economical to get rid of them.