Was this the title of a newspaper article? Titles have strange, special rules that are different from the rest of English.

There are many times when we use the present to refer to past events (see the Wikipedia article linked to below). In your example, I’d say it is because Mother Theresa is a historical figure who is important *today*. Her date of death *is* a historical fact that is valid to us in the present — not just an event in the past. In a way, she is immortal. Another example would be the “literary present”, where we talk about a book or movie in the present tense — the book / movie exists *now* and anyone can read it *now* or in the future. https://en.wikipedia.org/wiki/Historical_present

If you want to improve your English, isn't it better to try to understand an answer in English? ;) Can you give more context? You're right that it would normally be 'died', but that depends on the tense and time in the the next part of the quote. The writer may have switched tense to a present tense to tell a part of the story.

I agree with Chris -- it sounds like this is the title of an article (or maybe an item in a list), and not part of a normal "story." In normal speech or writing, it would be best to use the past tense here.