GEOFF BENNETT: We start today's other headlines with the latest back-and-forth in America's trade war with its northern neighbor.

The White House says a 25 percent tariff on steel and aluminum will go into effect at midnight tonight for Canada and other U.S. trading partners.

That's after trade adviser Peter Navarro said the U.S. will not be doubling those tariffs after all.

Earlier in the day, President Trump wrote on his social media platform that he's adding an additional 25 percent tariff on such products starting tomorrow.

Mr. Trump said this was in response to the province of Ontario raising prices for electricity coming into the U.S.

Following Mr. Trump's warning, Ontario's premier, Doug Ford, wrote on social media that the province had agreed to suspend its 25 percent surcharge on exports of electricity to Michigan, New York and Minnesota.

All this back-and-forth added to the unease on Wall Street today.

The Dow Jones industrial average lost nearly 500 points on the day.

The Nasdaq slipped about 30 points, but ended off its lows of the day.

The S&P 500 flirted with correction territory during today's session before ending about 40 points lower.

The National Transportation Safety Board is recommending a ban on some helicopter flights around Reagan National Airport in Washington, D.C.

It comes as part of their preliminary report on the January collision between an American Airlines jet and a Black Hawk helicopter that killed 67 people.

NTSB Chairwoman Jennifer Homendy said today that, under current protocol, helicopters flying a certain route can come within 75 feet of aircraft landing at the airport.

JENNIFER HOMENDY, Chair, National Transportation Safety Board: Seventy-five feet is very close.

That is far too close of a proximity.

We have stated it's an intolerable risk to aviation safety.

GEOFF BENNETT: Federal aviation officials had restricted helicopter flights around Reagan Airport immediately following the crash.

Now flights are put on temporary hold when helicopters need to pass by.

In the U.K., police arrested a 59-year-old man on suspected manslaughter in connection with yesterday's collision between two ships in the North Sea.

One sailor is presumed dead, while the 36 other crew members were safely rescued.

Aerial footage showed the cargo ship a drift and still on fire in some places 24 hours after it rammed into a stationary tanker.

That vessel, which had been transporting jet fuel, now has a huge gash on its port side.

Its owner said it's unclear exactly how much fuel spilled into the sea.

Environmentalists fear the crash could have lasting effects on wildlife, including fish and seabirds.

Former Philippine President Rodrigo Duterte has been flown to The Hague, where he faces charges of crimes against humanity before the International Criminal Court.

A jet said to be carrying Duterte was seen departing from the Philippine capital, Manila, after his surprise arrest by police.

The ICC is investigating the violent anti-drug crackdown during his time in office.

Thousands of people were reportedly killed by his police forces.

The 79-year-old has always defended his methods.

Today, he questioned the reason for his arrest in a video posted by his daughter on Instagram.

RODRIGO DUTERTE, Former President of the Philippines: What is the law and what is the crime that I committed?

So you have to answer now for the deprivation of liberty.

GEOFF BENNETT: Duterte himself withdrew the Philippines from the group of countries that recognized the court's authority back in 2019.

But judges at the ICC say their case is valid because their investigation involves killings that took place when the Philippines was still a member of the court.

In the Middle East, Israel has killed at least eight people in the Gaza Strip over the past 24 hours, adding pressure to an already fragile cease-fire with Hamas.

The "News Hour" captured this footage from the Netzarim checkpoint where an Israeli attack killed five Palestinians while they were inspecting their destroyed home.

That's according to our reporter on the ground.

The Israeli military said it had targeted a group of militants -- quote -- "engaged in suspicious activity."

The cease-fire has held since January, but talks over entering a second phase of the truce have stalled.

In Greenland, residents there voted in early parliamentary elections today with President Trump's ambition to take control of the island firmly on their minds.

TUUTA LYNGE-LARSEN, Nuuk, Greenland, Resident: We don't want to be a part of the USA, for obvious reasons like health care and Trump.

GEOFF BENNETT: While they're not actually voting on joining the U.S., Greenlanders will choose lawmakers who will shape the debate on that issue, plus future independence from Denmark.

The self-governing territory is home to some 56,000 people.

Unofficial election results are expected tonight, but they won't be certified for weeks.

Most of the world's population is breathing polluted air.

That's according to a new study from the Switzerland-based monitoring database IQAir.

Out of 138 countries monitored, Chad, Congo, Bangladesh, Pakistan, and India have the most pollution.

Only seven countries meet the WHO's clean air guidelines.

They include Australia, New Zealand and Estonia.

And only 17 percent of cities meet that bar, with Los Angeles having the dirtiest air in the U.S. Air pollution is believed to kill an estimated nine million people each year.

Still to come on the "News Hour": the Teamsters union president on the new labor secretary and President Trump's economic agenda; we look back five years after COVID-19 was declared a global pandemic; and taking stock of the cultural heritage lost in California's devastating wildfires.