The infection came from younger people who were spreading the virus. You know, those with a 99% survival chance ...
My 97 year old mother-law lives in an assisted living community. So I'm pretty familiar with the procedures there. There's probably a few hundred residents. They live in 1 and 2 person rooms. The problems is it's a close community. They all dine together. They all hang out together in the recreation room, Bingo room, TV room etc. The people who attend to them are very close. Depending on the resident, the staff helps them bathe, gets them dressed, gives them their medications, as well as a few nurses providing minor support services. The nurses and staff go from room to room, resident to resident. Visitors, including doctor calls, family visitors, oxygen delivery companies, etc. come and go adding to the mix. These visitors also see more than one resident at a time. The place is like a Petri dish. No other place is so dangerous for infectious diseases except possibly hospitals. Of course, hospitals have the experience and knowledge and equipment to deal with isolation. The staff working at old age homes are mainly aides who are inexperience with these things. Plus they don't have the PPE. So a lot of people died before they figured it out.
Today, my wife and I are not allowed to see her mom. The residents are not allowed out. All the staff have PPE and have had their training upgraded. How good is it? Who knows? My wife is close to her mom's support staff so she checks in constantly, even on skype video calls. She's satisfied that the staff is supplied with good PPE and work safely. They said they didn't need anything from us when we offered. We pray she'll be all right. It's a sad situation.