What if you knew her and found her dead on the ground? That was Neil Young’s compelling lyrical question about Allison Krause, one of four Kent State University students gunned down by the Ohio National Guard 50 years ago on May 4, 1970.Revealing news footage immediately provoked many questions from a nation already weary from relentless conflict in Southeast Asia and anti-war demonstrations at home. Young wrote his edgy protest song “Ohio” after seeing published photos of the shootings. It was promptly recorded by Crosby, …