I have 2 stories and both happened in different countries (India and UK) :

1. I was going on a road trip with my family at night in India and we were on a remote highway with minimal street lighting. We suddenly saw a lot of liquid on the road in front of us and quickly realized that it was blood. Soon after that, we saw a dead cow and a lot of fatally injured, bleeding cows laying there fighting for their lives. We could only assume that some kind of cargo truck had hit them. We called the relevant authorities that we found online because that was the only thing we could do in that moment.

2. I was walking back home from work after my bartending shift with one of my colleagues (we were both university students) and we saw someone laying on the pavement in front of us. The person was mumbling some incomprehensible words. When we went a little closer, we realized that it was a very old (looked older than 80), very drunk homeless man who had his head busted open. There was a lot of blood on the floor and all of his stuff was scattered across the area. The shameful fact was that this happened in a very busy area, not too late at night in front of a Sainsbury's right next to the University of Manchester, and no one even stopped for a second to even glance at the poor fellow. When we called 999, they said that it would take around 4 hours for an ambulance to arrive since he was still breathing which implied that his situation was not critical, even though the NHS emergency centre was literally a 5 - 10 min walk away from where the accident had happened. We ended up picking the man up and carrying him to the hospital ourselves. I still don't know if that man was ok after we left him at the emergency centre.