AMNA NAWAZ: In the day's other headlines: President Donald Trump signed an executive order today renaming Lake Ontario as Lake America.

It's part of his escalating trade war with Canada.

DONALD TRUMP, President of the United States: This is official, effective immediately.

AMNA NAWAZ: Trump made the name change official during a signing in the Oval Office this afternoon.

It requires federal entities to recognize the new designation, but it does not mean other countries have to do so.

Trump had threatened the change after talks broke down over his 50 percent tariffs on billions of dollars of Canadian goods, which took effect last weekend.

Canada then responded with levies of its own.

This afternoon, Prime Minister Mark Carney wrote on social media that Canadians know to call it Lake Ontario -- quote -- "now and always."

Federal aviation officials are reportedly moving to fire two air traffic controllers who allegedly left work early on the night of a deadly crash.

That's according to multiple media outlets citing sources.

Two pilots were killed and dozens injured when an Air Canada jet crashed into a fire truck in March.

Both employees are currently on leave.

Separately, federal investigators say that alerts from President Trump's helicopter to air traffic control went unheard before Marine One flew close to a passenger jet earlier this month.

They say ongoing construction at the White House may have been a factor.

But officials stress the president was never in danger.

An immigration officer facing charges related to a shooting in Minneapolis was released from a Texas jail today.

Christian Castro's release comes a day after a federal judge refused to order his return to Minnesota.

He's accused of firing his weapon through the front door of a Minneapolis home in January and wounding a Venezuelan immigrant.

Castro then falsely reported he had been attacked by the 24-year-old with a shovel.

The ICE officer was detained after a Minnesota judge issued a nationwide warrant for his arrest.

Minnesota officials fear he may flee to Mexico.

Russia says it launched what it called a massive attack against several Ukrainian cities overnight.

At least nine cities were targeted, including Kyiv, Zaporizhzhia, and the port of Odesa.

Ukrainian officials say at least two people were killed in the barrage and more than a dozen injured.

In the capital, jet-powered drones fell from the sky and black plumes of smoke rose from this warehouse just outside the city.

Also today, the Kremlin issued a new threat against the U.K.

in response to the country stepping up its support for Ukraine.

MARIA ZAKHAROVA, Spokeswoman, Russian Foreign Ministry (through translator): We have repeatedly warned that Ukrainian strikes on Russian territory using British weapons could prompt retaliatory attacks against any British military facilities and equipment in Ukraine and beyond.

AMNA NAWAZ: Meantime, authorities in Russia say a car bomb killed a military officer and injured his wife in a suburb of St.

Petersburg.

Local media identified him as a lieutenant colonel.

Officials have blamed Ukraine for a series of prior assassination attempts within Russia, some of which Ukraine has admitted to, while denying others.

The Bosnian Serb General Ratko Mladic, known as the Butcher of Bosnia, died in prison today.

Mladic led the Bosnian Serb army in the early 1990s.

Under his command, they pounded the besieged capital of Sarajevo as part of a broader conflict that left nearly 100,000 people dead and at least a million homeless.

He also oversaw the forces who carried out the 1995 massacre of at least 8,000 Muslim men and boys at Srebrenica.

It was Europe's worst atrocity since World War II.

One woman who lost two sons and a husband called Mladic one of the biggest war criminals.

MUNIRA SUBASIC, Relative of 1995 Massacre Victims (through translator): First of all, I am sorry that he died.

He should have suffered more.

He should have dreamt of our children's eyes; 31 years have passed, and us mothers are still carrying this pain in our souls.

AMNA NAWAZ: Mladic was already in poor health when he was arrested in 2011 after a yearslong manhunt.

During his trial, he remained defiant, even yelling at the judges when he was sentenced to life in prison in 2017.

U.N.

officials said today the 84-year-old Mladic died in a prison hospital in The Hague.

On Wall Street today, stocks ended higher after A.I.

giant Nvidia and others posted strong quarterly earnings.

The Dow Jones industrial average rose about 100 points on the day.

The Nasdaq jumped more than 1.5 percent.

The S&P 500 pulled closer to his record set earlier this month.

In China, the World Humanoid Robot Games are now over, but not before a robot sprinter broke yet another 100-meter record.

A Chinese humanoid beat Usain Bolt's world record for a third time yesterday, finishing almost a whole second faster than the Jamaican sprinter.

The ending, though, got a bit messy with sparks flying from one competitor.

Elsewhere, there were some stumbles in what are commonly called the Robot Olympics, but for the most part, more than 2,000 robots dazzled in dozens of disciplines like the long jump, tennis, martial arts, and boxing, among others.

And artist Yayoi Kusama has died.

She was one of Japan's most celebrated contemporary artists, known around the world for her signature polka dots and repetitive motifs.

Kusama first grabbed the art world's attention in the 1960s, showcasing her edgy sculptures and other works alongside the likes of Andy Warhol.

Those images laid the foundation for her mirrored Infinity Room installations in later years, which became social media sensations.

In 2017, she was featured on the "News Hour" speaking about her artistic attempt to reach the edges of our perception.

YAYOI KUSAMA, Artist (through translator): This effect of continual repetition calls out to the human senses and, in return, deep inside of our hearts, we yearn for true amazement.

AMNA NAWAZ: Kusama's legacy was tarnished later in life when her repeated racist comments against Black people came to light, including those made in her autobiography published in Japanese in 2002 and later in English.

She apologized for those statements.

Yayoi Kusama died earlier this month in her native Japan.

She was 97 years old.

Still to come on the "News Hour": what we know about the CIA director's clandestine visit to Moscow; why January 6 insurrectionists are still asking the Trump administration for restitution payments; and a leading hospital turns to improv comedy to help stave off dementia.