In the US, a janitor accidentally destroyed 25 years of research.

In Rensselaer Polytech's lab, one freezer made a nasty sound, and the janitor simply turned it off so that it wouldn't bother him. Inside were cell cultures and samples at -44°C, which were collected and studied for a quarter of a century. Now all the work will have to start over, and the damage is estimated at $1 million.