This happened a few weeks ago at school.

The previous semester we had to work in a group to make a basic Android application. After handing it in to the teacher, we had to present it in front off the class.

During this project, one of the groups was having some problems with a member, mainly because of misunderstandings and miscommunication. He definitely has technical skills, but he really needs to work on his focus and communicational skills.
The member was removed from the group and had to do it on his own. He had 2 days to make the app, which we initially got 2 weeks for.

Skip forward to presentation day.
Every group presented their app and got feedback from the teacher and the rest of the students.

Lastly, the guy that was on his own was giving his presentation. He started his powerpoint and explained what happened during the project and what went wrong. Then he said: "This is a black page in my school career, everything that could have gone wrong, went wrong". Immediately after saying this, he proceeds to go to the next slide: His laptop crashed, Blue Screen Of Death.

This was one of the most painful moments I've ever witnessed during a presentation.
I couldn't believe the timing of Windows to fuck up.