How do I find out who had POA over my grandfather when he passed in 2011?

Have you contacted other members of his family? I would think that would be the first start to learn more about the circumstances of his death. Since it seems you weren't that close, the family members would be the best source for information on how he died.

Have you been able to locate an obituary to determine which family members are still alive?

As to who held POA, I'm not sure it makes any difference at this point. Did you have any specific concerns in this regard?

The man dies several years ago and you only recently found out, but you need reassurance he didn't die alone? Seems to me to be too little too late.
If he had no one to care for him and died alone, what will it serve you to know that? And if some other relative or friend was looking out for him they will probably be p.o.ed that you are questioning their decisions now, I know I would be.

While I find your judgmental response unhelpful since you don't know ANYTHING about this situation, let me clarify things for you cwillie. My grandfather married my grandmother (her 3rd husband). She had 3 grown children when they found each other. I was a baby and he's the only grandfather I've ever known. He lived in BC, I lived in Ontario. The other grandchildren were East Coasters. Our family was spread out. My grandmother passed in 1991. Grandpa found a wonderful lady who filled the void left in his heart. I graduated from college and moved to the States. We kept in touch. I got to meet her 1 time (just before I got married) and never knew her last name. I just knew grandpa was happy. She had daughters in Vancouver (fully grown) with young children so he melded easily into a grandfather role again....... unfortunately this distanced him from me (miles as well as not being available). I wrote many letters (did I mention he was illiterate and couldn't read or write which requires his new lady to read them to him), but not sure if he got them. Received less and less correspondence from his girlfriend to the point it stopped. I have been looking for him since 2005. Apparently, they sold my grandparent's home and moved. Eventually my letters were sent back as 'not at this address'. There was no obit listed. He was a runaway who didn't recognize his family (he left when he was 10). I can't find out if his girlfriend was with him or maybe she's passed as well. I want to know how he ended up on the island from Surrey. I want to know he was loved by someone other than me. And I want YOU to know that before you hop on your high horse and pass judgment, make sure you're not on an ass first. Now, if anyone else has pertinent information for me, I would appreciate your response.

Mea culpa, I apologize.

My brother was able to find quite a bit of info through Ancestry website. He was able to privately email family members from a long lost branch and find out about great-great grandparents in Ireland. If you are completely stymied, that can be a starting place as there may not be much info if he was illiterate or was absorbed into the new family's clan. Many of the relatives my brother reached had no idea of this part of the family's existence. Hope you have luck. Also if you try googling, there are places that can look to see where a grave is and you can sometimes backtrack an area or people that way.

I'm hoping it was the daughter of his girlfriend. His family is not people I would ever want to find (according to why he ran away at the age of 10). His girlfriend and her kids were his family for 20 years (hopefully). I always addressed correspondence as 'Grandpa and *****' and she always signed with just her first name. There is no grave, he was cremated and set free. The elderly care facility and funeral parlor that handled the arrangements have been as helpful as they legally can. I did get a message about checking with the Clerk of the Court for his county of residence/passing. All of your suggestions are great! Please keep them coming!
Merry Christmas and Happy Holidays