@mikenov: Biden mourns loss of National Guardsmen killed in Mississippi crash | The Hill https://t.co/oitfEyxHJy The news marks the third major military helicopter incident in the past month. Booneville helicopter crash – GS: https://t.co/fTbbXSitS5 See also: Putin: Biden hit his head on… https://t.co/P2UiwqXzZC