In the village of Ayapa in the southern state of Tabasco, Mexico live two old men, Manuel Segovia, 75, and Isidro Velazquez, 69. They live a few hundreds yards from each other, but do not talk to each other. No one knows why they're not on speaking terms -- apparently they just don't much like each other.
This would hardly merit mention, but they are the two last speakers of Ayapaneco, which is the Spanish name for Nuumte Oote (True Voice) as it is called in their language.
The children of Segovia can understand it when he speaks it, but they can only pronounce a few words in the language. Segovia has tried to hold classes in the village, but as he explains, "I bought pencils and notebooks myself. The classes would start off full and then the pupils would stop coming."
When the two die, the language will die with them.
Daniel Suslak, a linguistic anthropologist from Indiana University, is compiling a dictionary of Nuumte Oote. Why? I don't know. It seems like a project that offers little return to me, but I suppoase it will go into a linguistic database and will be of some use in research.
You can read about it at the Guardian article Language at risk of dying out – the last two speakers aren't talking.
UPDATE: I found a video which I think is the two of them. I imagine they speak Nuumte Oote on it, but the narration is in Spanish, which is Greek to me, so I'm not sure if and when they speak the dying language.