On Thursday, President Obama said it is "certainly possible that there was a bomb on board" the Russian Metrojet airplane that crashed in Egypt's Sinai Peninsula Saturday, killing all 224 passengers and crew.

The president's comments came after Egypt and Russia both discounted concerns expressed by U.S. and British officials about a bomb being planted on the plane by Islamic State, with Egypt's Civil Aviation Minister Hossam Kamal saying in a statement that "the investigation team does not have any evidence or data confirming this hypothesis," and a Kremlin spokesman saying the West was pushing the idea there was a bomb onboard because of "geopolitical resistance to Russia's actions in Syria."

During an interview with KIRO Radio, Obama said he doesn't think anyone knows what exactly caused the plane to break up mid-air. "Whenever you've got a plane crash, first of all, you've got the tragedy, you've got making sure there's an investigation on site," he said. "I think there is a possibility that there was a bomb on board. And we are taking that very seriously.... We're going to spend a lot of time making sure our own investigators and our own intelligence community figures out exactly what's going on before we make any definitive pronouncements." Catherine Garcia

President Trump's good week just keeps getting better.

Late Monday, Acting Defense Secretary Patrick Shanahan said he'd let the U.S. Army Corps of Engineers use up to $1 billion of the military's budget to build a wall on the U.S.-Mexico border. The approval came in a letter to Homeland Security Secretary Kirstjen Nielsen, which specified that the money would go toward fencing, road improvements, and lighting near the border, CNN details.

In his letter, Shanahan specified that the $1 billion will fund 57 miles of "18-foot-high pedestrian fencing," per Bloomberg. It'll specifically be used "within the Yuma and El Paso Sectors of the border," and will also go toward "constructing and improving roads and installing lighting" in the area, Shanahan wrote. A league of Democratic senators quickly teamed up to write a response to Shanahan, saying he didn't ask congressional defense committees for approval before okaying the fund transfer.

Trump has long discussed using military money to build his border wall after Congress continually rejected his pleas for wall funding. Congress did give him $1.3 billion in the most recent budget, but Trump still declared a national emergency in an attempt to secure a few more billion dollars.

The Trump victory comes after Special Counsel Robert Mueller did not draw a conclusion on whether Trump obstructed justice, and after Attorney General William Barr decided not to charge the president on that crime. Kathryn Krawczyk

Fox News' biggest stars are going on the offensive.

Sean Hannity and Tucker Carlson took to the airwaves on Monday evening, just a day after Attorney General William Barr briefed Congress on the principal conclusions drawn from Special Counsel Robert Mueller's investigation into the Trump campaign's conduct surrounding Russian election interference in 2016. But they were not in a celebratory mood, despite the fact that they both said Barr's summary vindicates Trump — and them.

Instead, both hosts used the opportunity to lay into other networks, particularly CNN and MSNBC for peddling what they believe were lies — told deliberately to mislead audiences about the Mueller investigation, all in the name of conspiracy to increase viewership and profit. Hannity singled out a few publications like The Atlantic and The Huffington Post for writing headlines like "The Collusion with Russia Is in Plain Sight" and "Manafort indictment reveals Trump Russia Collusion," respectively. He expressed particular dismay that The New York Times and The Washington Post won Pulitzer Prizes for their reporting on the investigation.

"I am pissed off and so should the rest of the country be over what has happened," Hannity said. "We were lied to over and over again." Hannity, who has been an ardent Trump supporter throughout the process, also said that he is going to "hold every liar, every propagandist, every conspiracy theorist accountable."

Carlson expressed similar sentiments of anger toward the media. But he had a secret weapon — a leftist. The Intercept's Glenn Greenwald appeared as a guest on Carlson's show. Greenwald is, to put it gently, not of the same political persuasion as Carlson. But he is also known for being at odds with Democrats and a large swath of the media and over its coverage of the Mueller investigation, and he had some choice words for MSNBC and Rachel Maddow in particular. Tim O'Donnell

The first all-female spacewalk at the International Space Station was planned for March 29 with astronauts Anne McClain and Christina Koch, but it's now off because NASA doesn't have the proper spacesuit size available for McClain.

As NASA explains, McClain "learned during her first spacewalk that a medium-size hard upper torso — essentially the shirt of the spacesuit — fits her best." Since Koch also wears a medium, and only one suit in that size will be ready by Friday, the mission will now consist of Koch and a male astronaut, Nick Hague. NASA says that McClain is "tentatively scheduled" for a spacewalk on April 8 with a male astronaut, David Saint-Jacques.

While it might sound odd that McClain would just now be finding out what the right size for her is, Engadget points out that "there is no way to simulate the extended effects of zero gravity" on the body beforehand, also observing that McClain said in early March she had grown by two inches since she launched. And there actually are two medium sizes on the station; it's just that only one is configured for a spacewalk, and the other won't be ready in time for Friday, The New York Times reports.

NASA spokesperson Stephanie Schierholz told The Washington Post that despite this setback, the first all-female spacewalk is "inevitable." Brendan Morrow

Sen. Kamala Harris (D-Calif.) has revealed details of her proposal to give public school teachers a raise.

The 2020 Democrat is proposing an increase in federal spending with the goal of funding an average salary increase of $13,500 for public school teachers by the end of her first four years in office, CNN reports. The Harris campaign says this will cost $315 billion over 10 years, and she plans to pay for it with changes to estate tax, per NBC News.

Harris' proposal involves the federal government in the first year providing 10 percent of the funding to states to close what she has described as the salary gap between teachers and other college-educated graduates, Vox explains. States would receive incentives to contribute, and in subsequent years, the federal government would provide $3 for every $1 from the state.

Harris said during a recent speech per The Wall Street Journal that with this proposal, the question is "what's the return on the investment," and "on this, the investment will be our future." Brendan Morrow

MMA fighter Conor McGregor just announced his retirement — for the second time.

McGregor, who earned himself a six-month suspension in January for his role in a post-fight brawl after UFC 229, announced early on Tuesday that he is retiring "from the sport formally known as 'Mixed Martial Art.'" He added that he wishes "all my old colleagues well going forward in competition" and now joins "my former partners on this venture, already in retirement."

But no one was sure whether to take McGregor's announcement at face value, especially because he previously said he was retiring in 2016. "I have decided to retire young," he tweeted at the time. McGregor took this back just two days later, but his retirement could be real this time, with the phrasing of his tweet suggesting he could continue his career in boxing or wrestling. It's a real boy-who-cried-wolf scenario.

McGregor's Tuesday announcement also came just hours after his appearance on The Tonight Show Starring Jimmy Fallon, during which he said he's "in talks" for his next UFC fight in July and that he's "ready" for it, although "we'll see what happens" because "there's a lot of politics." The timing led fans to speculate McGregor's retirement announcement is simply a negotiating tactic.

UFC President Dana White reacted to McGregor's news Tuesday by saying that "it totally makes sense" and that "if I was him, I would retire too," per MMA Junkie. It remains to be seen how real all of this is, but if this retirement announcement is anything like the previous one, we may only need to wait two days to find out. Brendan Morrow

The hope among some Democrats that President Trump might be removed through impeachment took a hit when House Speaker Nancy Pelosi (D-Calif.) poured cold water on the idea earlier this month. Special Counsel Robert Mueller's final report, as filtered through Attorney General William Barr, appears to have quashed those hopes completely, "at least for now," The Washington Post reports.

Pelosi "and members of her leadership team agreed in a Monday night huddle that the caucus needs to stop talking about collusion with Russia because it was distracting from their legislative agenda." Notably, three people familiar with the meeting told the Post, liberal Rep. David Cicilline (D-R.I.) and Trump-district Rep. Cheri Bustos (D-Ill.) "both argued that the House needs to megaphone pocketbook issues that won them the majority."

House Democrats still plan to demand Barr release Mueller's complete report and supplemental material, and members of all ideological stripes say it's important to continue investigating Trump's administration and actions, the Post said. "Some House Democrats suggested Monday that they will double down on a strategy of attempting to cripple Trump with what one aide described as 'a thousand cuts.'"

The group of Democrats least affected by Mueller's report may be the 2020 presidential candidates, who haven't been talking much about Mueller or impeachment and aren't being asked about the subject. "Indeed, Democratic strategists have long said their party's best message for next year's election — absent a stunning revelation from the Mueller report — would focus on pocketbook issues like health care," McClatchy reports. "Polls show voters care more about those subjects, and Democrats were able to use a message fixated on protections for pre-existing conditions to gain 40 seats in the House last year." In that realm, at least, Trump is providing plenty of fodder. Peter Weber