Methuselah dies
Methuselah, the longest-lived person in the Bible, died at 969 in the year of the Flood.
All the days of Methuselah were nine hundred sixty-nine years, then he died.
Genesis 5:27 (World English Bible)
Methuselah was the son of Enoch and the grandfather of Noah. Adding up the ages in Genesis 5 puts his death in the very year the Flood came.
Dating notes
Scripture doesn't say whether he died before the rain began; many assume so. His name is sometimes explained as 'when he dies, it will be sent,' but that meaning is uncertain.