KNOW IT ALL: Friday’s Top 7 Stories at NBC News

Good morning. Here are some of the stories we're following today:

1. Trump’s Rivals Slam Him, Then Vow Their Support

Donald Trump's rivals and Fox News' debate moderators laid out a clear and factual case on Thursday that the billionaire's policies were unworkable, that he regularly shifted his positions and that he had engaged in business practices he routinely denounces on the campaign trail. Read more in POLITICS.

Watch the Best Moments From the GOP Debate 2:05

2. Here’s How a Contested Convention Could Happen

The delegate math is becoming increasingly clear: The March 15 Florida and Ohio contests will determine if Donald Trump is the sure-to-be Republican nominee or if there's a contested GOP convention. And there doesn't appear to be any other possibility, given that the nominee needs to win 1,237 delegates to win a majority. Read more in POLITICS.

3. North Korea Makes Nuclear Threat Amid Anti-U.S. Rhetoric

North Korean leader Kim Jong Un ordered his military on standby for nuclear strikes at any time, state media reported Friday, but U.S. officials said there was no evidence that it had prepared to deploy any such weapons. Read more in NEWS.

4. Possible MH370 Debris Will Be Studied ‘Next Week’

Investigators leading the hunt for Malaysia Airlines Flight MH370 said Friday it will be several days before debris found by a U.S. adventurer arrives in Australia for analysis by experts. Read more in NEWS.

5. Soccer Star Brandi Chastain Will Donate Brain to Science

Chastain's gray matter is going to Boston University researchers studying chronic traumatic encephalopathy or CTE, a degenerative brain disease that has been found in athletes who suffered concussions during their careers. Read more in SCIENCE.

6. Former Death-Row Inmate Held Woman Captive: Cops

Claude Lee Wilkerson has been charged with keeping a woman captive and sexually assaulting her for months in Colorado, officials said. Wilkerson was convicted in a deadly armed robbery in Houston in 1979, but was freed from death row four years later over inadmissible evidence. Read more in NEWS.

Woman Held Captive for Months by Former Texas Death-row Inmate 1:20

7. Fleeing to Europe: Follow the Mediterranean Route

Desperate migrants used to leave Europe by the thousands, fleeing war, poverty and persecution. But if Europe used to populate the world, the world is now populating Europe — and a new era of exclusion is just getting started. Read more at MSNBC.

Nightly Spotlight

Some golfers wait their entire lives for a hole-in-one, but Taylor Crozier managed to get it out of the way before his 12th birthday — and did it in front of a golfing legend.

11-Year-Old Christens Tiger Woods' New Golf Course With Hole-in-One 0:24