Today, Deir Yassin Day, April 9, falls on a Friday, just as it did in 1948.
Deir Yassin was an Arab-populated village (it was mono-ethnic; no Jews allowed) that participated in anti-Jewish violence in 1920 including gun-running, in 1929 with attacks on nearby Jewish neighborhoods of Givat Shaul and Bet HaKerem, in 1936-1939, especially aiding terror attacks on the Tel-Aviv - Jerusalem highway and in April 1948, participated in sniping attacks on Bayit VeGan and Bet HaKerem, allowing Iraqi irregulars as well as Arab guerrillas to reside in the village.
On the night of April 8 and into the day of April 9, militants, members of two Jewish anti-British occupation armed forces sought to rid the village of armed persons who were disrupting the peace, seeking to thwart a United Nations resolution and killing innocent civilians.
An attempt was made to warn the villagers of the impending attack by use of a loudspeaker which largely failed due to an anti-tank trench that the attackers had not been aware of previously however many did flee towards another Arab village, Ein Karem. During the attack, armed Arab disguised themselves in feminine attire. In the ensuing battle, five members of the attacking force were killed and over 40 were injured, fully one-third of the force.
In the street fighting and house-to-house combat, 120 Arabs at the most, and perhaps fewer, were killed. Many, including women and children, were prevented from leaving their homes and so suffered fatal wounds.
The news of the fall of the village developed into a wild rumor-mongering which caused thousands of Arabs, many not at all threatened, to flee. This, ironically, facilitated future Jewish victories on the field of battle as they repelled Arab aggression.
In a later BBC documentary, "The 50 Years War", Arab residents of the village admitted that claims that a massacre took place were highly exaggerated.