From a linguistic point of view, Latin is alive and well. Due to the nature of linguistic evolution, Latin evolved into Spanish, Catalan, French, Romanch, Rumanian, Italian, Portuguese, and countless dialects therein, very very gradually, on a continuum. Therefore, any native speaker of Latin, or evolution thereof, which i will call L1, L2, L3, and so on, would be able to understand anybody 200-300 years before or after him. It is therefore incorrect to say that Latin died, because there is a continuous chain of mutually intelligible speakers.
Labelling a language based on the area where it is spoken is at best a convenient convention, and does not mean in any way that those languages listed above are not in actuality L426.
To further illustrate my point, Gothic is a dead language. The tribe was wiped out, and the language went with them.
Now, that being said, I’ve heard that St. Isidore of Seville was the last speaker of Latin.
And really, the title of this thread is incorrect. Since there are still some priests who know Latin, it cannot even be considered dead. At most, somebody should give it last rites…