GEOFF BENNETT: Welcome to the "News Hour."

One of the world's most hunted men is dead.

Hamas military leader Yahya Sinwar was killed by Israeli troops yesterday in Southern Gaza.

The news of his killing came today, and, after DNA testing, Israel confirmed the mastermind of the October 7 attacks on Israel was indeed dead.

AMNA NAWAZ: Those terror attacks just over a year ago killed more than 1,200 Israelis, the deadliest single day for Jews since the Holocaust.

The war Sinwar launched led to a brutal military response by Israel to destroy Hamas, killing tens of thousands of Palestinians in Gaza, mostly women and children.

Nick Schifrin is here now with the latest -- Nick.

NICK SCHIFRIN: Amna, for months the U.S. and Israel have dedicated vast resources to try and find Sinwar, who they believed was hiding in tunnels.

But, in the end, Sinwar died posing as a regular fighter, not in a tunnel, not surrounded by hostages, not wearing a suicide vest.

And the Israeli soldiers who killed him had no idea he was there.

And a warning: This story contains disturbing images.

The death of one of the world's most wanted men was, in the end, by chance.

Yesterday, soldiers from tank and infantry training units operating in Rafah got in a firefight.

The Israeli military released this drone video as it searched a house.

They saw an unidentified fighter still alive.

And they fired again.

That's when they entered the house and realized they recognized him and found documents and money.

They took his body and confirmed with DNA tests it was Yahya Sinwar, the military and political leader of Hamas and the architect of the October 7 terrorist attack.

Israel's top general, Herzi Halevi, visited the area and credited Israel's plan to push through Rafah despite international resistance.

LT. GEN. HERZI HALEVI, Chief of Staff, Israeli Defense Forces (through translator): We conducted many special operations in this war where we had excellent information and pinpoint accuracy.

Here, we didn't have that.

And yet the response was very, very strong.

NICK SCHIFRIN: Today is a religious holiday in Israel.

And across the country, they celebrated Sinwar's death.

MAN: Bye-bye, Sinwar.

NICK SCHIFRIN: But Israelis and senior U.S. officials say their immediate concern is the 100 remaining hostages believed to be held in Gaza by mid-level Hamas leadership in tunnels.

Israeli Prime Minister Benjamin Netanyahu: BENJAMIN NETANYAHU, Israeli Prime Minister (through translator): Today, evil has suffered a heavy blow.

But the task before us is not yet complete.

To the dear families of the abductees, I say, this is an important moment in the war.

We will continue with all our strength until the return home of all your loved ones, who are our loved ones.

NICK SCHIFRIN: But Israeli and American officials also hope Sinwar's death is the beginning of the end of the war.

Pockets of Hamas fighters still attack and release videos showing targeting of Israeli tanks.

Today, Netanyahu made them an offer.

BENJAMIN NETANYAHU (through translator): Whoever lays down his weapon and returns our hostages, we will allow him to go out and live.

The return of our hostages is an opportunity to achieve all our goals, and it brings the end of the war closer.

NICK SCHIFRIN: The U.S. hopes the end of the war, including a hostage release, can launch reconstruction and larger diplomatic efforts to provide Gaza new leadership.

President Biden this afternoon in Berlin: JOE BIDEN, President of the United States: Now is the time to move on, move on -- move toward a cease-fire in Gaza, make sure that we're moving in the direction that we're going to be in a position to make things better for the whole world.

It's time for this war to end and bring these hostages home.

NICK SCHIFRIN: Sinwar grew up in Khan Yunis and helped found Hamas as its chief enforcer.

In 1998, Israel arrested him.

In over 23 years in detention, he learned Hebrew, studied Israeli society, and even received lifesaving surgery in an Israeli hospital.

In 2011, in exchange for a single Israeli soldier, Israel released Sinwar and more than 1,000 Palestinian prisoners.

He was welcomed back to Gaza a hero.

He became Hamas' Gaza chief in 2017, a disciplined and dictatorial leader.

He always described himself as a soldier who will die amongst his fighters.

But he also convinced Israel he wanted a long-term status quo.

That was a bluff.

He helped design the deadliest attack in Israeli history to be so violent, so brutal, and involve so many hostages it would help ignite regional war.

The fighting has spread to Lebanon and between Israel and Iran.

He believed Palestinian and Israeli deaths were a necessary tool in reigniting the Palestinian cause.

But the war he helped launch has destroyed Gaza and the lives of its people.

He also defined victory as his and the group's survival.

And today, Geoff, Sinwar and nearly all of Hamas' leadership is dead.

GEOFF BENNETT: Nick, we know that the U.S. secretary of state, Tony Blinken, is heading to the region.

What's his goal for this trip?

NICK SCHIFRIN: Try and make progress on hostages and the day after.

On hostages, he hopes that new leadership in Hamas would be willing to make a deal that Sinwar is not, but it's not clear Hamas will have new leadership in time to even make that decision.

And on the day after, the U.S. has been negotiating with Arab partners to take over security in Gaza as a transition to Palestinian Authority governance.

But there's no agreement between Arab partners or with Benjamin Netanyahu.

And so the U.S. does see this as an opportunity, but knows it will be difficult to translate it into diplomatic and political progress.

GEOFF BENNETT: Nick Schifrin, our thanks to you, as always.

NICK SCHIFRIN: Thanks, Geoff.