Talk:Tenno/@comment-213.105.202.130-20150309135810/@comment-7645613-20150310032059

According to various lore the tenno slaughtered them, so it's implied that they either died in that instance or slowly were picked off by the infested that remained, as the tenno were called into cryosleep.

at the same time, it is implied that the tenno destroyed the sentients as the tenno came back 'victorious' although it's clear either they did not kill them all off and the rest of the sentients went into hiding until now (update 16)or they were all killed but the beacon we activated in that last quest sent a signal to some sentient group somewhere as a call to tell them the tenno have been awakened again.

i'm assuming that arcane device was placed as such so only someone powerful enough could collect all the pieces and assemble it. that's just my speculation anyway.