Boa Sr was apparently the last speaker of the Great Andamanese language Bo (or Aka-Bo, described as extinct in the Ethnologue). According to Survival International there were around 5000 Great Andamanese in 1858 , when the British invaded the Andaman Islands. Now there are around 50 – killings, diseases and forcible resettlement having caused the decline. See Vanishing voices of the Great Andamanese (VOGA).
Boa Sr died in January, and her death has made headlines in many newspapers – there’s an article about her in the Guardian [thanks Simon]. Survival International has more information, including a short film clip with her singing in Bo – other songs are listed at VOGA. They also have a campaign on to support other Andamanese groups, especially the Jarawa, whose survival is under threat from settlers, poachers and loggers. The Sentinelese of North Sentinel Island have resisted contact, and Survival International urges the Indian Government to respect this, and to put a stop to poaching.