The search for the missing airliner that vanished en route from Malaysia to China is reportedly focusing on Malaysia’s west coast, far from the opposite coast where the plane last made contact with air traffic control. Now in its fourth day, the disappearance of Malaysia Airlines Flight 370 is being described as one of the greatest aviation mysteries in history. Some 239 passengers were on board, including two allegedly traveling on stolen passports.

El Salvador’s election tribunal says a former rebel leader has an “irreversible” lead in presidential elections. The latest results show Salvador Sánchez Cerén besting right-wing candidate Norman Quijano by just over 6,000 votes. The tribunal is recounting ballots from disputed polling stations only, while Quijano is calling for a full recount. The tribunal is expected to formally declare the winner on Wednesday. If his lead holds, Sánchez Cerén would be the first FMLN president to succeed another after decades of right-wing rule. Sánchez Cerén fought with the FMLN when it was a guerrilla group and political party battling U.S.-backed military governments in the 1980s.

Japan is marking the third anniversary of the Fukushima Daiichi crisis, when a massive 9.0-magnitude earthquake triggered a devastating tsunami on its northeast coast. The twin disasters resulted in an unprecedented triple meltdown at the Fukushima Daiichi nuclear power station. Internal emails revealed by NBC News show in the days after the meltdown, regulators in the United States made a concerted effort to downplay the potential of a similar crisis occurring on U.S. soil. The campaign included refusing to answer media questions on disaster preparedness, spinning journalists on key data, and even hiding Japanese engineers from reporters visiting the Nuclear Regulatory Commission in Maryland. The effort came despite widespread internal doubts over the safety of aging U.S. plants. In a memo to staffers about the agency’s public talking points, the NRC’s head of public affairs writes: “While we know more than these say, we’re sticking to this story for now.”

Senate Democrats have staged an all-night filibuster to urge congressional action on global warming. The all-night marathon began at 6:30 Monday evening, with over two dozen senators taking part. Senators Edward Markey of Massachusetts and Barbara Boxer of California said Republicans who deny global warming are ignoring an existential threat.

Sen. Edward Markey: “The planet is running a fever, but there are no emergency rooms for planets. We have to engage in the preventative care so that we deploy the strategies that make it possible for our planet to avoid the worst, most catastrophic effects of climate change.”

Sen. Barbara Boxer: “We all know that all senators care deeply about their constituents and their families; if any one of us saw a danger looming, we would do everything in our power to save them. And yet, in the face of irrefutable scientific agreement, the Senate does nothing to make sure that polluters pay for the carbon they emit which will move us to a clean energy economy and away from catastrophic climate change.”

Despite the unprecedented effort to promote climate action, it took over three hours before the first call was heard for what environmentalists see as one of the most immediate and important steps that Washington can take: rejecting the Keystone XL oil pipeline. Senator Tim Kaine of Virginia made the demand, saying: “Why would we embrace tar sands oil and backslide to a dirtier tomorrow?” Environmentalists say Keystone would produce a devastating amount of carbon emissions through the extraction of tar sands oil in Canada.

As the Senate held its climate filibuster, protest actions against the Keystone XL continued nationwide. Over 20 people were arrested outside the Federal Building in Philadelphia on Monday, protesting the conclusions of a State Department report that said the pipeline’s construction wouldn’t “significantly” worsen climate change.

Meanwhile, it appears the State Department made a key error in assessing the Keystone XL’s environmental impact. In its report, the State Department said the pipeline would have little impact on tar sands extraction either way because the oil would easily be moved by rail should the Keystone XL be rejected. The report cited industry projections of moving around 200,000 barrels of oil per day by train. But according to Reuters, the company behind the pipeline, TransCanada, has moved just a quarter of that amount — 40,000 barrels — during its peak deliveries of oil by rail.

The Senate has overwhelmingly approved a measure to overhaul prosecution of sexual assault in the military. Passed by a unanimous 97-to-0 vote, the bill scraps the century-old “good soldier defense” that allows defendants to present evidence during trial of a positive military character. The bill also gives accusers a voice in whether cases are heard in civilian or military courts and increases requirements for commanders. But the bill is considerably weaker than a measure rejected by the Senate last week, which would have moved oversight of sexual assault in the military to outside the chain of command.

Hundreds of people gathered on both sides of the U.S.-Mexico border on Monday to support a group of youths seeking re-entry into the United States. It was the third action in two years in which people deported from Mexico tried to return to the U.S. without legal documents. The National Immigrant Youth Alliance organized the action to call attention to record deportations and the stalled efforts at immigration reform. Joselyn Rodriguez, whose father was deported three years ago, traveled with her sister from North Carolina.

Joselyn Rodriguez: “I’m waiting for my dad, and I’m waiting for all the other families that are out here, because it’s not just me — it’s not just about me, it’s not just about my sister; it’s about everybody that’s out here.”

Around 30 people tried to enter on Monday, seeking a humanitarian visa or asylum. The action focused on DREAMers — young people left without legal status after coming to the United States as undocumented children. Entire families will attempt to re-enter the U.S. later this week. In the coming days, the Obama administration is set to hit a record milestone of two million deportations since taking office. Deportations separated over 150,000 U.S.-born children from their parents last year, the majority under 10 years old.

As activists and immigrant families challenge deportation on the U.S.-Mexico border, a hunger strike is continuing at a Washington state immigration jail. Around 750 prisoners at the Northwest Detention Center are refusing meals in protest of the Obama administration’s record deportations as well as poor conditions that include wages of just one dollar a day for prison labor. Supporters now say the strikers are reporting increased retaliation from prison officials, including isolation and threats of forced feeding. Asylum seekers are also allegedly being threatened with the denial of their bids. A rally in support of the hunger strike is set to take place outside the prison later today.

Thousands of people marched to the Florida State Capitol on Monday in a rally against the state’s “Stand Your Ground” law. Attendees included the Reverend Al Sharpton and the parents of Travyon Martin and Jordan Davis, two unarmed black teens killed in Florida in the last two years. Trayvon’s mother, Sybrina Fulton, said Florida is failing people of color, while Jordan’s mother, Lucia McBath, said the movement will refuse to back down.

Sybrina Fulton: “Florida is an 'F' state. 'F' is for Florida, because right now Florida is failing us.

Lucia McBath: “We will continue to fight. We will continue to stand. We are not going away.”

Opponents want the law’s repeal, but Florida Republicans are pushing a measure that would expand its reach. A new bill advanced last week would make it legal to fire a warning shot at a potential attacker. The NRA-backed proposal would ostensibly benefit defendants like Marissa Alexander, a black woman sentenced to 20 years in prison for firing a warning shot near her estranged husband. Alexander faces up to 60 years at her retrial. But opponents fear the expanded leeway could lead to even more shootings of unarmed people of color.

The rally in Florida against “Stand Your Ground” comes days after Trayvon Martin’s killer, George Zimmerman, made his latest public appearance — signing autographs at a gun show in Orlando.

The House Energy and Commerce Subcommittee has opened a probe into regulators’ failure to heed complaints about defective ignition switches in General Motors’ vehicles, which have been tied to 13 deaths. General Motors recalled some 1.6 million cars last month over an ignition flaw that shuts down engines and disables air bags. According to The New York Times, the National Highway Traffic Safety Administration failed to launch an investigation despite receiving over 260 complaints about the ignition failures in the last 11 years.

Leaders of 15 Caribbean countries have adopted a platform calling for slavery reparations from Europe. The 10-point declaration from CARICOM asks Europe to issue a formal apology, forgive debt and help descendants cope with the psychological impact of slavery’s legacy.

NSA whisteblower Edward Snowden gave a rare public speech Monday at the South by Southwest Interactive Festival in Austin, Texas. It was the first time Snowden has directly addressed a U.S. audience since he left the country last May. Snowden spoke via video stream from Russia, where he has been granted asylum.

Edward Snowden: “The NSA, the sort of global mass surveillance that’s occurring in all of these countries, not just the U.S. — and it’s important to remember that this is a global issue — they’re setting fire to the future of the Internet. And the people who are in this room now, you guys are all the firefighters. If data is being clandestinely acquired, and the public doesn’t have any way to review it, and it’s not legislatively authorized, it’s not reviewed by courts, it’s not consonant with our Constitution, that’s a problem.”

Snowden added that he believes his whistleblowing has improved U.S. security and that he wouldn’t hesitate to leak the same NSA files again. Journalist Glenn Greenwald also addressed the festival later in the day, following a speech by WikiLeaks’ Julian Assange on Saturday via video stream from the Ecuadorean Embassy in London, where he has sought political asylum since 2012.

A Canadian photojournalist and activist has died while covering the civil war in Syria. Ali Mustafa and six others were killed Sunday in a Syrian government airstrike on the northern town of Aleppo. Mustafa’s photographs of the Syrian conflict captured the plight of besieged civilians. In an interview with Canada’s CTV News Channel after his first trip to cover the Syrian conflict last year, Ali Mustafa discussed his attempt to document Syria’s suffering.

Ali Mustafa: “As a journalist, I think it was important to be there to tell the story as it was emerging as one of the major developing issues right now, and as well as being a natural outgrowth of some of my other work in the region, having visited previously. … You basically just have to do as best you can to be aware of your surroundings and try to stay safe, and capture as many quality photos as you can under those circumstances.”

In addition to his photojournalism abroad, Ali Mustafa was also a dedicated activist in his home city of Toronto, focusing on issues of poverty and the treatment of prisoners detained without charge under so-called “security certificates.” More than 100 people honored Mustafa’s life at a vigil in Toronto on Sunday.