On September 27, Lorretta Webster passed away, one of the last native speakers of Oneida (one). She began working with the Oneida revitalization program in 1996 when she was in her eighties.
You can read more about Lorretta Webster in the article in the greenbay pressgazette.
According to the Ethnologue, Oneida was estimated to have 250 speakers in Canada and the US in 1991. Wikipedia says there are an estimated 160 speakers, of which only about six learned the language as infants.
Oneida Language Tools provides resources for learning Oneida.