This trick made me think. After thinking, I came to this idea:
1st There is a site where each of us can register and indicate their home address. Until now, this address is not visible to anyone.
2nd Every day we come there and confirm that we are alive. It can be via the Internet, via SMS, or less.
Three If there is no news from someone (say, two days), then he is dead. Then everyone is told his address, we go to the place, break the door and get into the apartment.
4 is The cat was rescued.