Israeli soldiers killed Hamas leader Yahya Sinwar, the architect of the Oct. 7 attack, in a death that leaves a huge hole at the top of the militant group and spurred fresh U.S. pressure for Prime Minister Benjamin Netanyahu to end the war in the Gaza Strip.

The Israeli military said Sinwar, who hadn’t been heard from in weeks, was slain Wednesday in southern Gaza along with two other Hamas militants in what appeared to be a chance encounter with the mastermind of the deadliest attack on Israeli soil.

One person familiar with the incident said Israeli forces spotted suspicious movement inside a building while on a routine patrol.