This is 100% true, it didn't happen to me, but I can assure you that I've heard if from various sources and think it's interesting to share. The office block where my mother works (I rather not disclose the company name, but I can assure you, that you all know it and have used their products if you have a car), is a relatively new building, constructed under 20 years ago, very modern, all glass on the outside. During its construction, one of the builders putting a windows on the 3rd floor fell out of the building and died.
There are security guards in this building, 24 hours a day, 365 days a year. Keep in mind this is the main office for the Mediterranean sector of one of the most important worldwide companies. During the months after summer (September, October...) at night every day during night watch, guards seem to find the same window that the dead worker was putting in to be open, with an office chair next to it. After moving the chair and closing the window, they find the same thing to happen again in the next watch, another interesting fact is that you need key-cards to access the lifts and they seem to also move up and down constantly being called by and to different floors all by them selves.
Many security staff has left their job because of this, and the head of security seems to reject actually inspecting the 3rd floor. How do I know this? Well I know a few of my mother's work colleagues and she is head of human resources and is a type of person who wouldn't lie about these things, so I know if from her.
What do you think, about this?