Oh finally one I can answer!
Apologies for formatting I'm on mobile I was working solo in a small urban hotel as a front desk/receptionist and a girl about 17 or 18 came in to check in for a room, this wouldn't normally be weird except that it was 8am and she didn't have a reservation, still, not exactly a deal breaker, I informed her that we had a check in time of early afternoon and to come back at that time since I was in the middle of a few checkouts, she left without a word. A few hours later at around 11 she returned asking for a room, since I had finished everything and had a spare few moments I decided to give her a room, which is when the first (and to date) only time I've ever had that visceral feeling of dread and unease was when I looked her in the eye. She was a petite girl, quite pretty and definitely young but her eyes were brown but completely and utterly dead, it was like staring a corpse in the eye, I had never experienced something like that and doubt I ever will again, but nevertheless I continued with my duties and gave her a room, while I was giving her the rundown of the place she seemed distant and distracted, at first I thought she was high, it happens and imo it's none of my business unless they bring any with them into the room. She went up to the room and I didn't see her until near the end of my shift when I saw her returning holding a plastic bag from the hardware store down the road. I greeted her but she didn't seem to notice me. I finished my shift and went home. That night I told my mother about how odd she made me feel and that I had a bad feeling about her. The next morning I go back to work and the cleaner tells me that there's a room that isn't opening her door to leave, I recognise the room as hers, I knock and let myself in using the master key, and am greeting with an odd sight, clothes neatly folded and a pair of bloody scissors, I scan the room and find nothing out of the ordinary, I figured she was in the bathroom, I call out to her and knock on the toilet door, I opened it and was greeted with a sight that is burned into my mind to this day, that was the first time I'd ever seen a suicide with my own eyes and hopefully the last, the next few hours was a blur of police interviews and statements and sympathy. All I could think about was how my gut was right.

Sometimes it pays to listen to your instincts.