My Initial Reaction Was Less than Somber

All you need to know about him in one picture
Hamas leader Yahya Sinwar was killed in a firefight in Gaza.

Rather refreshingly, this did not involve dropping a large bomb in an area largely populated by non-combatants.  

It also appears that this was happenstance, and not an intelligence coup.

Hopefully, this will lead to an end of hostilities:

Hamas leader Yahya Sinwar was killed early Thursday in the Gaza Strip, the IDF confirmed. Hamas sources told Reuters that there are indications that suggest that Sinwar had been killed in an Israeli operation in Gaza. The IDF added that there were no signs of the presence of hostages in the area in which Sinwar was killed.

A DNA sample from the body was sent to the Institute of Forensic Medicine, and dental images were sent to the police's forensic science unit. The DNA sample was compared to a sample from Sinwar collected when he was in Israeli prison. The military and the Shin Bet security service said that there have been dozens of operations over the past year and the past few weeks in the area where Sinwar was killed, which "limited Yahya Sinwar's ability to act... and led to his elimination."

Money, identification documents and combat equipment were found on the bodies of the terrorists. The troops that encountered the terrorists were not in the area for a targeted killing operation and did not have prior intelligence that Sinwar was present there.

The soldiers that killed the three are in training to be squad commanders, and are not part of a commando unit. It was operating in the area to locate Hamas members. Before dawn on Thursday, the troops began to suspect that there were Hamas members in the building and opened fire, including the use of tank shells and shoulder-fired missiles. Troops subsequently used drones to examine the building and located the bodies. Explosive devices had been planted in the building. Combat engineers were deployed to the site and neutralized them.

So it appears that his killing was just luck, though as Branch Ricky noted, (He might have been quoting John Milton) "Luck is a residue of design."

The world is a better place without him.  When he was jailed by the Israelis, it was for torturing and murdering Palestinians.

He was a particularly nasty piece of work, even by the standards of the region.

One hopes that this will provide an opportunity for the fighting to end, but I do not think that this is the case, and I lay that on the door step of Benjamin Netanyahu (יִמַּח שְׁמו), who will do anything to stay in power and out of jail, including prolonging the carnage.

………

Einav Zangauker, the mother of hostage Matan Zangauker, reacted to the news by addressing Prime Minister Benjamin Netanyahu, saying, "You got your image of victory. Now reach a deal." She added that "now, more than ever, the lives of my son Matan and the other hostages are in concrete danger... Netanyahu, [Defense Minister Yoav] Gallant, and the chief of staff have already said themselves that Hamas has been defeated militarily. A year after the failure [on October 7], this is the time to leverage the accomplishments and use [Sinwar's] elimination to take a diplomatic step that will bring our loved ones back home."

She added, "If Netanyahu does not take advantage of the momentum and does not stand up now and take a new Israeli initiative, even at the cost of ending the war, it means that he has decided to abandon my Matan and the other hostages, with the aim of prolonging the war and entrenching his rule."

Netanyahu is a greater threat to the state of Israel than Sinwar ever was.