AMNA NAWAZ: In today's other news: Russian American Ksenia Karelina is flying back to the United States tonight after 14 months in Russian captivity.

She was released as part of a prisoner swap, the second since President Trump returned to the White House.

Here's Nick Schifrin.

NICK SCHIFRIN: A smiling Ksenia Karelina today on her way back home, after being released from Russian custody in video filmed by Russia's spy agency.

She was arrested last February and sentenced to 12 years in a maximum security prison colony for committing treason.

The U.S. called that absolutely ludicrous.

Her crime?

A donation of $51.80 to a U.S.-based humanitarian group that helps Ukrainians affected by the war.

Karelina was a former ballerina and lived in Los Angeles for more than a decade.

Her boyfriend, Chris Van Heerden, told us last February how much she was missed.

CHRIS VAN HEERDEN, Boyfriend of Ksenia Karelina: She's kind, loving, funny, loved by all her friends.

Everyone who meets her wants more of Ksenia.

She is funny as hell.

She has so much life in her.

NICK SCHIFRIN: Karelina was part of a swap engineered by CIA Director John Ratcliffe for Arthur Petrov, who flew back to Russia today.

He was arrested for smuggling military-grade electronics to Russia in violation of U.S. sanctions.

Today, President Trump said he hoped the swap could turn into more diplomatic momentum.

DONALD TRUMP, President of the United States: We spoke to President Putin about it and they made a deal.

They released the young ballerina and she is now out and that was good.

So we appreciate that.

We hope that we're going to be able to make a deal relatively soon with Russia and Ukraine to stop the fighting.

NICK SCHIFRIN: But, so far, Russia has refused President Trump's request for a full 30-day cease-fire, that despite a previous prisoner swap, U.S. teacher Marc Fogel exchanged for a Russian cyber-criminal.

As for Karelina, she will reunite with her boyfriend tonight and they will head straight to a rehabilitation facility for recently released detainees.

For the "PBS News Hour," I'm Nick Schifrin.

AMNA NAWAZ: Also today, a helicopter crashed into New York's Hudson River just off Manhattan.

All six people who were on board, including a family of Spanish tourists, were killed.

Three were children.

Eyewitnesses reported seeing the helicopter break apart in midair.

The crash prompted a massive rescue and response.

Boats circled the Bell 206 aircraft, which could be seen mostly submerged and upside down in the water.

What caused the crash is unclear at this early stage.

It is routine for the skies above New York City to see numerous plane and helicopter flights that are private and recreational or commercial.

In another aviation incident, two American Airlines passenger planes clipped wings on the tarmac of Reagan National Airport in Washington.

One of the planes had several members of Congress on board.

No injuries were reported on either jet.

Air traffic control operations at Reagan have come under intense scrutiny since the fatal collision in January between an American Airlines flight and an Army helicopter that killed 67 people.

Well over 200 people are confirmed dead from a nightclub roof collapse in the Dominican capital of Santo Domingo.

Today, some rescue efforts gave way to recovery operations as hope fades for finding survivors.

Across town, mourners wept for Rubby Perez, the merengue icon who was performing on Tuesday night when the ceiling caved in.

For other restless families, no word yet on their missing relatives.

YAEFREISI MALENO, Relative of Nightclub Attendees (through translator): We learned that there are two relatives of ours.

Their vehicle was here.

There are videos of them dancing here, and that's how we found out.

So far, they have not given us any clues.

We have gone to the hospitals.

We have searched.

We have been attentive when they take the bodies out, and nothing.

AMNA NAWAZ: Officials said 189 people have been rescued alive from the rubble.

The government says it'll launch an investigation into what caused the collapse when recovery operations finish.

The Trump administration announced a lofty goal today.

Health and Human Services Secretary Robert F. Kennedy Jr. said that his agencies will identify the cause of autism by September of this year.

Kennedy gave that pledge today during a Cabinet meeting with the president.

He cited a sharp rise in cases in recent decades.

ROBERT F. KENNEDY JR., U.S. Health and Human Services Secretary: We have launched a massive testing and research effort that's going to involve hundreds of scientists from around the world.

By September, we will know what has caused the autism epidemic, and we will be able to eliminate those exposures.

AMNA NAWAZ: Kennedy's efforts will build upon decades of research into whether genetic or environmental factors might contribute to autism.

He's frequently linked autism with vaccines, which has been debunked by the scientific community.

While inflation generally cooled here in the U.S. last month, there was one notable exception, eggs.

The average retail price hit a record high in March at $6.23 per dozen.

That came as a bit of a surprise to some industry experts because wholesale costs had decreased significantly and egg farms suffered no new bird flu outbreaks.

Experts say shelf prices may drop when demand falls after Easter.

And two of the world's biggest names in fashion are set to unite.

Prada has struck a nearly $1.4 billion deal to buy Versace from us luxury group Capri Holdings, bringing the brand back to Italian ownership.

The high fashion icons are known for contrasting styles.

Prada won't be involved in the creative side of Versace, and the executive said there aren't plans for changes at CEO.

Versace had taken financial losses over the last few quarters, while Prada has defied a luxury market downturn with sustained growth.

The deal is expected to close later this year.

Still to come on the "News Hour": why President Trump is directing the Justice Department to investigate two members of his last administration; the debate over daylight saving time reaches Capitol Hill; and musician Nile Rodgers reflects on the origins of his career and artistry.