Are you talking about Delta Sky Miles or Amex points? Two different things. Delta (according to the T & C's) consider the miles to be Delta's until they are used. If someone passes away, Delta feels the miles are theirs and they won't transfer them to anyone else. If you have access to the delta.com account, you should be able to use the miles without any issues. Just don't tell Delta the person is deceased. If you are talking about Amex points, that is different. One way or the other, if you cancel the Amex card, Amex will not contact Delta to advise them of the death. My wife passed away 2 1/2 years ago. I cancelled her Amex and continued to use her Delta miles until they were depleted.