The success of the operation was assisted by the death of Al-Hussayni in combat . During this time , and independently of Haganah or the framework of Plan Dalet , irregular troops from Irgun and Lehi formations massacred a number of Arabs at Deir Yassin , an event that , though publicly deplored and criticized by the principal Jewish authorities , had a deep impact on the morale of the Palestinian population
Deir Yassin
Deir Yassin massacre
Plan Dalet