Announcer from nbc news World Headquarters in new york, this is nbc nightly news with Brian Williams. Good evening. To the First Responders who arrived, it looked like the deafen oifgs terrorism. Inside a synagogue in jerusalem two palestinians entered with cleavers, knives and a gun. Five people dead, three rabbis. Among the dead three americans. Its the deadliest single attack in six years. It comes at a time of already high tensions. Tonight israel has ordered the homes of the killers be destroyed, and in terms of retaliation, they may just be getting started. Now this has the worlds attention. We begin there with bill neely. Reporter outside a jerusalem synagogue, police are targeting two killers. Its just minutes after the men have shot and stabbed four people to death. In the exchange of fire, one policeman is shot and injured before both gunmen are killed. Inside, its a blood bath. Around two dozen men have been praying when they were attacked with axes, butchers knives and a pi