The Kafr Qasim massacre occurred on October 29, 1956. That day, the Israeli government issued a curfew on several towns, including Kafr Qasim. Israeli Arabs were under a regime of martial law at the time.
At about 5pm, several dozen locals attempted to return home, unaware of the curfew. They were then shot at by members of the Israel Border Police. Forty-eight persons were killed, including 19 men, 6 women, and 23 children under the age of 18. Arab Israelis often cite the number of those killed as 49, due to one of the women who were killed being pregnant at the time.
The Border Police soldiers who fired the deadly shots were tried and convicted in a case that set a precedential legal example for what's called a "blatantly illegal order"—an order which, if received, a soldier has a duty to refuse.