'Start Here': China strikes back in trade war, Trump warns Iran, David Muir visits Notre Dame

It's Tuesday, May 14, 2019. Let's start here.

1. The empire strikes back ... at the other empire

Markets tumbled on Monday as China retaliated to the latest retaliation by the U.S. as leaders of the world's two largest economies still can't hammer out a reasonable trade policy.

Beijing announced it would implement new tariffs on $60 billion worth of American goods in retaliation for President Donald Trump's decision to raise tariffs on $200 billion in Chinese imports.

Americans haven't felt much impact yet from the tariffs, but the escalating dispute could prove devastating, ABC News Senior National Correspondent Terry Moran tells "Start Here."

"We are going to start noticing," he tells us, "that we are in a trade war and there are casualties."

2. 'Suffer greatly'

After four ships were targeted in attacks off the coast of the United Arab Emirates, Trump warned Iran: "If they do anything, they will suffer greatly."

The initial U.S. assessment is that Iran or Iranian-backed proxies were responsible for placing explosive charges on the tankers, according to a U.S. official.

"This wasn't an attack directly onto U.S. forces or U.S. ships in the region, but it's certainly not going to sit well," ABC News' Elizabeth McLaughlin says.

3. Breyer's dissent

As the Supreme Court announces its final opinions of the term over the next few weeks, conservatives are anticipating the court takes up one of several possible abortion cases that sets up a fight over Roe v. Wade.

Abortion rights advocates were alarmed on Monday by an apparent warning of "which cases the court will overrule next" from Supreme Court Justice Stephen Breyer after a 41-year-old precedent was overturned in a state-sovereignty case.

"What that means is, the conservative majority is willing to overturn precedent, they're not afraid to do it," ABC News' Devin Dwyer, who covers the Supreme Court, explains. "In this case… [Breyer] certainly has abortion on his mind."

4. Notre Dame exclusive

Weeks after a massive blaze devastated the historic Notre Dame Cathedral in Paris, "World News Tonight" Anchor David Muir was given an exclusive look inside.

The damage was "haunting," says Muir, who also felt a sense of hope because so much of the 850-year-old building remains.

"What was abundantly clear to me and the team as we walked in," he shares with us, "was that the cathedral will be alive and well again."

"Start Here," ABC News' flagship podcast, offers a straightforward look at the day's top stories in 20 minutes. Listen for free every weekday on Apple Podcasts, Google Podcasts, iHeartRadio, Spotify, Stitcher, TuneIn or the ABC News app. Follow @StartHereABC on Twitter, Facebook and Instagram for exclusive content and show updates.

Elsewhere:

'Thoughts and prayers': At least four are dead after a midair collision in Alaska.

'Deep regret and shame': Felicity Huffman pleads guilty to her role in the college admissions scam.

'It's just an unfortunate consequence of multiple billions people on earth and all we consume': In the Mariana Trench, the deepest point on the planet, an explorer finds plastic.

'There was no way in hell that I was going to allow some coup or coup attempt to take place on my watch': Still, the president of the United States of America insists on repeating unsubstantiated claims of a potential coup.

From our friends at FiveThirtyEight:

North Carolina's do-over U.S. House election starts Tuesday: The residents of North Carolina's 9th Congressional District have gone more than four months without representation in the U.S. House after the North Carolina State Board of Elections declined to certify the 2018 election because of allegations of election fraud. On Tuesday, the district, which stretches from Fayetteville to the eastern Charlotte suburbs, will take its first step toward filling that empty seat when it goes to the polls for the primaries.

Doff your cap:

A 14-year-old has pledged to eliminate the sizable lunch debt of a 129-school district in Texas.

Ben Hofer, an eighth grade student at St. Andrews Episcopal School, recently crowdfunded $8,000 for a project he's dubbed "LunchCounts!" He plans on putting the money toward nearly $18,000 of school lunch debt in the Austin Independent School District.

"I was never expecting to raise this much money, really honestly," Ben told "Good Morning America." "It's pretty crazy, but the more the better, I guess, because it's more kids we could pay off."

Ben kicked off his initiative on GoFundMe on April 21 as part of a semester-long school project in which students dig into a community issue. He said he chose this project to tackle "lunch shaming."

"If we could get to the whole debt, that'd be really cool," he said. "I don't think we'll get there by the end of the school year, but you never know."