Good morning. Here are some of the stories we're following today:
1. Storm System Strikes Northeast After Killing 8 in South
A deadly storm that sparked dozens of tornadoes across the Southeast focused its fury on the Northeast early Thursday — leaving hundreds of thousands without power, canceling hundreds of flights and wreaking havoc on the roads. Read more in NEWS.
2. Rubio Attacks Trump By Name Ahead of Debate
In an abrupt about-face in strategy, Marco Rubio on Wednesday night attacked Donald Trump on policy by name from the stump, drawing the battle lines for a certain showdown with the GOP front-runner on the eve of Thursday's debate. Read more in POLITICS.
3. Cracks Emerge in GOP Opposition to Front-runner Trump
As Trump racks up delegates and makes it more difficult for the four remaining challengers to catch up with him, some major GOP donors are questioning the purpose and efficacy of efforts to derail Trump's candidacy. Read more in POLITICS.
4. Should Apple Help Customers Hide Info From Government?
The government's attempt to force Apple to bypass iPhone security features in the San Bernardino terror investigation raises fundamental questions about data privacy in the digital age, experts tell NBC News. Read more in INVESTIGATIONS.
5. White House Vetting GOP Centrist Governor for SCOTUS
Nevada Gov. Brian Sandoval, a Republican centrist, is as a potential nominee for the vacant seat on the Supreme Court, NBC News has confirmed. Although he is a Republican, Sandoval's record matches President Barack Obama's on many key issues. Read more in POLITICS.
6. Elections in Iran Offers Choice Between Reformers, Hard-Liners
Iranian voters are set to go to the polls Friday in an election that could set the stage for a reformist comeback or see hard-liners tighten their hold on the country. Read more in NEWS.
7. ER Visits Double for Pot-Using Colorado Visitors
Emergency department visits involving marijuana-using visitors doubled from 2013 to 2014, the first year cannabis use was legalized in Colorado, a team of Denver-area doctors said. Read more in HEALTH.
From space, Scott Kelly talks to Lester Holt about what he's looking most forward to back here on Earth after nearly a year on the International Space Station.