For me it happened during a trip. Since I was as little as 2yo my granpa would take me to trips with him and his wife.I really look up to him and my relationship with him is so close he's like my second father. Anyways, when I was 16 my grandparents and I went to this trip to Australia, the furthest destination we've ever travelled to. 20+ flight hours, 13h time zone difference from home, you get the idea. A week prior to our departure my Grampa starts feeling sharp pains in his knee, two days after it stops and he figures we are clear to embark on our journey. Skip to our arrival in Melbourne, he can't walk because of the knee pain which had just come back. In the hotel I requested for a wheelchair and took him to the room, thinking we could just rest the night (needless to say we were rather tired), and by the next morning sort things out, call travel insurance, go see a doctor, etc. While I was sleeping, my grandma, who had been showing slight signs of dementia lately, starts shouting at Grandpa about why he's keeping her locked in her their house. He opened the room door, showed her the hotel hallway, tried his best to try to make her understand we were on a trip, not at home, which just made her more angry. At 6 AM he wakes me up and drags me to the bathroom, and explains the situation."srbesta, your grandmother has gone crazy! Please help me, I don't know what to do"- said the teary eyed man who until then was the beacon of answers to me. That's when it hit me. I was literally halfway around the world having to take care of injuried grandpa who was seeking ME for help, and handle my grandma whose mental condition was absolutely unpredictable, as the only one of the 3 capable of speaking english. Going back was not possible due to my grandma's agressiveness and stubborness, and having some family member come and help was not exately financially viable, besides it would take a day or two. It turns out my grandpa's knee had nothing serious, in 10 days he was all healed. My grandmother however has Alzheimer's and her crisis was probably triggered by lower oxygen levels in long haul flights. After the 1st day she calmed down and we could go on with our trip, even with her completely desorientated and unaware of where we were and him on a wheelchair.

Tl;dr - went to a trip to Australia, my grandpa had a misterious knee injury, and I found out grandma has Alzheimers. Had to deal with both issues alone in a foreign country.