Good morning. Here are some of the stories we're following at NBC News.
1. Scott Walker enters Republican presidential race
The governor of Wisconsin becomes the 15th candidate to enter the GOP field. In a YouTube video, he calls for “new, fresh leadership with big, bold ideas from outside of Washington.” Read more in NEWS.
2. Eurozone leaders and Greek PM reach deal
The agreement on a third bailout is meant to keep nearly bankrupt Greece among the countries that use the euro. The deal, which includes privatization of some state assets, must be ratified by reluctant Athens lawmakers. Read more in NEWS.
3. ‘El Chapo’ is master of the underground tunnel
He's known as "Shorty" — but perhaps "The Mole" would be more accurate. The Mexican drug lord who disappeared from prison on Saturday lives by the tunnel, frustrating all those who try to catch him. Read more in NEWS.
4. Storm and tornado threats loom over 47 million
Damaging winds, heavy rain and lightning are possible for a broad section of the country from Wisconsin to Ohio and Kentucky. Then the rough weather moves into the Southeast. Read more in NEWS.
5. Killer of American teacher executed by UAE
State media say the United Arab Emirates has put to death a woman convicted of terrorism after the militant-inspired killing of a kindergarten teacher in December. Read more in NEWS.
6. Nintendo president dies at 55
The company says a bile duct growth was the cause of death for Satoru Iwata, who led Nintendo to major growth over 15 years — with big help from the Wii and DS game consoles. Read more in NEWS.
7. Probe focuses on Pluto’s moon — and Vader Crater
The NASA mission known as New Horizons should deliver a sharper picture by Tuesday, and if astronomers give the OK, it could lead to the naming of a dark crater after Darth Vader. Read more in SCIENCE.