At 9:00 PM, April 1, 1959, Kol Israel's main radio program opened with an announcement of a call-up of the reserves, followed by three military code words.
These were broadcast without warning about an upcoming call-up exercise, thus raising a general alarm in Israel. Israelis were sure that a war is about to break any minute; tensions rose in the neighboring Arab countries; the Egyptian and Syrian armies conducted emergency call-ups, and the Jordanian army was put on alert.
On the morrow, April 2, 1959, the IDF's spokesman announced that the call-up was part of a routine exercise, intended to verify the units' speed of response to a public call-up.
David Ben Gurion, prime Minister and Minister of Defense at the time order the establishment of a committee of inquiry, headed by the jurist, Ya'akov Shimshon Shapira.