JOHN YANG: Good evening, I'm John Yang.

Death and destruction in southern Gaza today.

Palestinian officials say a targeted Israeli airstrike killed at least 90 people that would make it one of the deadliest attacks of the war.

Israel says the target was Hamas military chief Mohammed Deif thought to be the chief architect of the October 7 attacks.

Hamas says he wasn't in the area at the time of the strike.

Israeli officials don't deny that it took place in a part of Khan Younis that was designated as a safe place where displaced Palestinians were living in tents.

ABDALLAH ABU MADI (through translator): End this war, this is enough.

There is no safe zone in Gaza.

End this war, have mercy on us and our children.

We are getting killed every minute.

JOHN YANG: In addition to the dead hundreds of others were wounded.

Hamas says the attack is proof that Israel isn't interested in a ceasefire agreement.

President Biden was again working to shore up support today speaking virtually with groups of moderate and Progressive House Democrats.

Vice President Harris was on the campaign trail in Pennsylvania.

She told a town hall organized by an Asian American group that this is the most important election for American democracy.

KAMALA HARRIS, U.S. Vice President: One thing we know about our President Joe Biden, he is a fighter.

We will continue to fight.

We will continue to organize, and in November we will win.

JOHN YANG: This week's PBS/News NPR/Marist poll of registered voters found no difference in support for Mr. Biden and Vice President Harris in head to head matchups with Donald Trump.

He'd supported by 50 percent of those polled, Trump got 48 percent against the President and 49 percent against terrorists.

Russia and Ukraine traded more attacks today.

Ukraine says Russian shelling killed four people along the front lines while Ukraine's latest long range drone attack started a fire in an oil depot deep inside Russia's Southwestern Rostov region.

In Paris Olympic organizers still intend to use the river Seine for some events despite concerns about its cleanliness.

Today, the French Sports Minister took a dip in an effort to dispel worries while years of efforts have improved the water quality data from city testing shows that as recently as last week, there were days of unsafe levels of fecal bacteria.

There was to be the venue later this month for the swimming leg of a triathlon and for marathon swimming.

And pioneering sex therapist Dr. Ruth Westheimer has died.

Known simply as Dr. Ruth in the 1980s.

She talked plainly and candidly about things rarely discussed in public at the time.

She became a pop culture icon with her own TV and radio shows.

Born in Germany and orphaned by the Holocaust, her varied life experiences included being trained as a sniper in Israel's War of Independence.

Ruth Westheimer was 96 years old.

Still to come on PBS News Weekend, why children in residential treatment centers are vulnerable to abuse and U.S. attempts to crack down on Russian disinformation through social media.