The most common process leading to language death is one in which a community of speakers of one language becomes bilingual in another language, and gradually shifts allegiance to the second language until they cease to use their original (or heritage) language. This is a process of assimilation which may be voluntary or may be forced upon a population. Speakers of some languages, particularly regional or minority languages, may decide to abandon them based on economic or utilitarian grounds, in favour of languages regarded as having greater utility or prestige. This process is gradual and can occur from either bottom-to-top or top-to-bottom.
anyway, linguists think that when less than 4 millions people speak a language , it gonna die by itslef. (Latvia population-2010 estimate 2,245,357 (143rd))
So , it's sad , but it seems that it's a lost battle