It's "historical present". The historical present is the use of a verb in the present tense to refer to an event that happened in the past to sound more important. It is widely used in writing fiction to sound dramatic, for news headlines and narratives etc. The verbs usually represent an even in the past.

Because it's sort of still in the present tense, he just died so to let the audience/reader know this was a recent development - they are using "dies" instead of "died". Either way, heart breaking news for us in America : (

https://en.wikipedia.org/wiki/Historical_present

It happened so recently, if feels like the present. Newspapers want to be very current, so it is better to use the present tense in the news. It sounds more like a Twitter feed. John Kennedy died in 1963. Was it that John McCain died a few days ago? No, it just died now. So, John McCain dies.

Because its referring to the age of 81, the at 81 marks the current time he died. I hope you get my explanation maybe someone else can say it clearer.