On October 6, 1973, Egypt and Syria conducted coordinated lightning raids on Israel, catching them by total surprise. It was Yom Kippur, the holiest day of the year in Judaism, when Jews, even in their military, pray for atonement. The air raids were on Israeli airbases, defence installations in Sinai, Central Israel, Golan Heights, Hawk missile batteries, command centres, artillery and radar groups. Simultaneously 32,000 Egyptian infantrymen crossed the land border.