Three that come to mind immediately are:
The Tote Bag Incident
As I was walking into work one morning, a very polite male co-worker held the door open for me. He was visiting our office from our site in India, so I didn't know him at all except by sight. As I passed through the door I turned kind of sideways so as not to brush against him and in doing so, the tote bag I was carrying, which contained two cans of diet Pepsi in addition to some other objects, swung around with a good deal of momentum and hit him squarely in the...umm...coconuts.
The Slit Skirt
During a rare quiet moment when I worked at an urgent care I was standing in the reception area with my back to the waiting room, doing some filing. I was wearing a knee-length black skirt with a small V-slit in the back. Suddenly my co-worker Sally, who always spoke at jet-engine-level volume, practically screamed, "Hey bansidhe, did you know your skirt has a slit in it?" Confused, I answered, "Yes, it's supposed to." She shouted in response, "Well it goes up kind of high so I thought I should say something."
So everyone in the very crowded waiting room got to find out along with me that the back seam in my skirt had come unraveled to about mid-butt level.
When I worked weekend shifts at an animal hospital, Mrs. Smith frequently came in to pick up medication or food for her poodle Pierre. She'd been doing this for some time so even though I worked emergency shift and never saw her or Pierre when they came in for regular appointments, I always recognized her and asked how Pierre was doing.
One Saturday afternoon Mrs. Smith dropped by the hospital when I was working and I cheerfully, said, "Hi! What's Pierre up to these days? Are you here to pick up food for him?"
She responded, "He died the day before yesterday. I'm here to pick up his ashes."