10 Things to Know: This Week's Takeaways 1110

Looking back at the stories to remember from the past week:

1. FORT HOOD AGAIN THE SCENE OF A DEADLY SHOOTING RAMPAGE

Spc. Ivan Lopez killed three people, wounded 16 and then turned his gun on himself Wednesday at the sprawling Texas military base. Lopez had an argument with soldiers in his unit before opening fire, authorities said Friday. In 2009, Army psychiatrist Nidal Hasan killed 13 people and wounded more than 30 at the base.

2. AWARD-WINNING ASSOCIATED PRESS PHOTOGRAPHER ANJA NIEDRINGHAUS KILLED

The 48-year-old photographer was shot to death by an Afghan police commander who also wounded AP correspondent Kathy Gannon in the eastern city of Khost. Niedringhaus had covered conflict zones from the Balkans to Iraq, Libya and Afghanistan and was part of a team of AP photographers who won the Pulitzer Prize in 2005.

3. WHITE HOUSE SAYS 7.1 MILLION SIGN UP FOR HEALTH CARE

The total, announced Wednesday, was an unexpected comeback after a disastrous rollout that included problems with the website. In a preview of his party's midterm election messaging, President Obama declared that while the health law isn't perfect, "the Affordable Care Act is here to stay."

4. MYSTERY OF MISSING MALAYSIA AIRLINES FLIGHT 370 PASSES FOUR-WEEK MARK

Two ships deployed sound locators in the Indian Ocean in a desperate attempt to find the plane's flight data and cockpit voice recorders before their signal beacons fall silent. The air and sea search has not turned up any wreckage from the plane, which vanished March 8 en route from Kuala Lumpur to Beijing with 239 people aboard.

5. SENATORS OK RELEASE OF A REPORT CRITICAL OF CIA INTERROGATIONS AFTER 9/11

Thursday's vote on the secret report by the Senate Intelligence Committee sets the stage for what could be the fullest public accounting of the Bush administration's record concerning waterboarding and other "enhanced interrogation techniques." The White House said it would instruct intelligence officials to cooperate fully.

6. MOZILLA CO-FOUNDER QUITS AS CEO AFTER PROTESTS OF HIS ANTI-GAY-MARRIAGE STANCE

The nonprofit that makes the Firefox browser angered many employees and users last week by naming Brendan Eich head of the organization. At issue was Eich's $1,000 donation to the 2008 campaign to pass California's Proposition 8, a constitutional amendment outlawing same-sex marriages. The ban was overturned last year when the U.S. Supreme Court left in place a lower-court ruling striking down the ballot measure.

7. LAWMAKERS ACCUSE GM OF POTENTIALLY CRIMINAL COVER-UP ON DEADLY DEFECT

CEO Mary Barra underwent testy and aggressive questioning Tuesday and Wednesday in Congress over the automaker's defective ignition switches. She gave assurances that the cars, mainly Chevrolet Cobalts and Saturn Ions, are safe to use while owners wait for a replacement part. She said many of the answers Congress is seeking will come out in an internal GM investigation in 45 to 60 days.

8. POWERFUL EARTHQUAKE OFF CHILE CAUSES SURPRISINGLY LIGHT DAMAGE, WITH 7 DEATHS

The magnitude 8.2 quake hit Tuesday night in the Pacific. Thousands were evacuated from parts of Iquique due to the threat of a tsunami, which lifted boats onto streets and sank others. It also touched off landslides that blocked roads, knocked out power, damaged an airport and started fires that destroyed several businesses.

9. DAVID LETTERMAN TO RETIRE FROM CBS' 'LATE SHOW' IN 2015

Letterman, who turns 67 next week, made the announcement during a taping of his show Thursday. He'll be ending three decades on the air — the longest tenure of any late-night talk show host in U.S. television history — since he launched "Late Night" at NBC in 1982.

10. BASEBALL OPENS ITS SEASON — AND LAUNCHES EXPANDED VIDEO REPLAY

When 26 major league teams began play Monday after a long winter, it also featured the first two umpire calls — one in Milwaukee, the other in Pittsburgh — to be reversed via the new video review system. Baseball was the last among the major sports to use technology to confirm or overturn decisions by its umpires, employing it mostly for home runs since 2008 and vastly expanding its use this year.