In New Zealand, at least 49 people have died, and dozens have been hospitalized with gunshot wounds, after a gunman attacked two mosques in the city of Christchurch during Friday prayers. It was the deadliest shooting in New Zealand’s history. Police have arrested and charged a 28-year-old Australian man named Brenton Tarrant, who is described by authorities as a right-wing extremist. Tarrant live-streamed the attack on Facebook and published a manifesto in which he praised President Donald Trump as “a symbol of renewed white identity and common purpose.” Three other people—two men and one woman—were detained nearby, but at least one of them has already been released. New Zealand’s Prime Minister Jacinda Ardern called the massacre a terrorist attack and said it was one of her country’s darkest days.

Prime Minister Jacinda Ardern: “Many of those who will have been directly affected by this shooting may be migrants to New Zealand. They may even be refugees here. They have chosen to make New Zealand their home, and it is their home. They are us. The person who has perpetuated this violence against us is not. They have no place in New Zealand.”

The entire city of Christchurch was placed on lockdown, with residents told to shelter in place. Authorities haven’t ruled out the possibility of other suspects, and asked people not to attend mosques across New Zealand today out of fear of another attack. We’ll have more on the unfolding tragedy in New Zealand after headlines.

President Trump appeared to threaten his political opponents with violence in an interview published Thursday by the far-right website Breitbart. Trump accused his opponents on the left of “playing tough” but said his supporters are tougher, telling Breitbart, “I have the support of the police, the support of the military, the support of the Bikers for Trump—I have the tough people, but they don’t play it tough—until they go to a certain point and then it would be very bad, very bad.”

Connecticut’s Supreme Court has reinstated a wrongful death lawsuit against gun maker Remington Arms brought by family members and a survivor of the 2012 Sandy Hook Elementary School shooting. The massacre saw 20-year-old Adam Lanza use a Remington-manufactured AR-15 Bushmaster semiautomatic rifle to kill 26 people—including 20 first graders—in less than five minutes. Thursday’s ruling in Connecticut opens the door for families to subpoena internal documents from gun makers, which could reveal how corporate executives sought to appeal to young people in marketing campaigns and ads. One such advertisement featured an image of an AR-15 with the caption, “Consider your man card reissued.”

Meanwhile, hundreds of students left classrooms in the Washington, D.C., area and marched on the Capitol to demand new gun control laws. Similar protests played out around the country, marking the first anniversary of the March for Our Lives rally against gun violence organized by survivors of the Marjory Stoneman Douglas High School massacre in Parkland, Florida.

In a stunning rebuke to the White House, the Senate on Thursday voted 59 to 41 on a resolution reversing President Trump’s declaration of a national emergency on the U.S.-Mexico border. Trump declared an emergency on February 15 in order to raid federal funds to pay for a border wall after Congress refused his request for nearly $6 billion. A dozen Republicans crossed the aisle to vote in favor of the measure, which had already been approved by House lawmakers on Tuesday. Ahead of the vote, Trump tweeted, “A vote for today’s resolution by Republican Senators is a vote for Nancy Pelosi, Crime, and the Open Border Democrats!” This is Republican Susan Collins of Maine.

Sen. Susan Collins: “It is a solemn occasion involving whether or not this body will stand up for its institutional prerogatives and will support the separation of powers enshrined in our Constitution.”

After the Senate voted to nullify his national emergency, Trump tweeted a one-word response: ”VETO!” Congress does not yet appear to have the two-thirds majority needed to override a presidential veto, meaning the issue is likely to be decided by federal courts. Trump is planning a veto-signing ceremony at the White House today.

Meanwhile, the House of Representatives voted 420 to 0 on a resolution calling for special counsel Robert Mueller’s final report on the Russia investigation to be made public once it’s complete. Republican leaders are resisting efforts by minority Democrats to introduce a companion bill in the Senate.

Thousands of schoolchildren are leaving classrooms in over 100 countries around the world today, in a “school strike for climate” demanding immediate, urgent action to curb global warming. In the U.S., students organized some 400 protests in all 50 states. This is 13-year-old activist Alexandria Villaseñor, who helped organize today’s walkouts in New York City.

Alexandria Villaseñor: “Civil disobedience is called for, because there hasn’t been enough action in the climate conversation. World leaders aren’t enacting the right policies and laws that need to happen to keep us below 1.5 degrees.”

Today’s mass protests were sparked by 16-year-old Swedish climate activist Greta Thunberg, who has skipped school every Friday to sit outside the Swedish parliament to demand leaders act on climate. This week, three Norwegian lawmakers nominated Thunberg for the Nobel Peace Prize.

New York City will invest a half-billion dollars to protect Manhattan from sea level rise due to climate change. Mayor Bill de Blasio announced the plan Thursday, which would allocate funds to four projects aimed at protecting Manhattan’s southern tip, home to Wall Street and the city’s Financial District. The funding is a small fraction of the $10 billion Mayor de Blasio says is needed to keep flooding from storm surges and rising seas at bay in the coming years.

The Trump administration is preparing to open vast areas of the Atlantic Ocean to oil and gas development—and a top Interior Department official is praising President Trump’s ability to distract the media for allowing the project to proceed. Records obtained by The Guardian show Joe Balash, the assistant secretary for land and minerals management, told a recent meeting of the International Association of Geophysical Contractors, “One of the things that I have found absolutely thrilling in working for this administration is the president has a knack for keeping the attention of the media and the public focused somewhere else while we do all the work that needs to be done on behalf of the American people.” The Trump administration’s Atlantic Ocean drilling plan would permit oil and gas leases in federally controlled coastal waters up to 200 nautical miles from the shore.

Irish Prime Minister Leo Varadkar met with President Trump and Vice President Pence in Washington Thursday as part of an annual trip ahead of St. Patrick’s Day. Varadkar, who is gay, brought his partner, Matthew Barrett, to his meeting with Mike Pence, before calling out the vice president over his long history of opposing LGBTQ rights.

Prime Minister Leo Varadkar: “I stand here, leader of my country, flawed and human, but judged by my political actions and not by my sexual orientation, my skin tone, gender or religious beliefs. And I don’t believe that my country is the only one in the world where this story is possible.”

President Trump said Thursday he plans to visit to the Republic of Ireland at some point this year.

Israeli warplanes dropped bombs across the Gaza Strip overnight, hours after Palestinians fired rockets toward Tel Aviv for the first time since 2014. No one was injured by the Palestinian rocket fire, while news agencies in Gaza said the Israeli strikes injured four Palestinians, including a woman who had her hand amputated. Israel’s military said it had targeted 100 “Hamas military targets,” though Hamas and two other Palestinian groups—Islamic Jihad and the Popular Resistance Committees—all denied responsibility. Israel’s military now says it believes Hamas members fired two missiles “by mistake” as they performed maintenance on the rockets.

In southeastern Africa, Tropical Cyclone Idai made landfall late Thursday in Mozambique, bringing high winds and flooding to a region already inundated by storms. Over the past week, heavy rains in Mozambique and Malawi have killed at least 115 people and left thousands of homes destroyed.

In the United Kingdom, lawmakers have asked the European Union for more time to craft a Brexit plan, after they failed to reach agreement on how to exit the EU ahead of a March 29 deadline. Under the plan, Britain would see a short delay to Brexit if lawmakers agree to a plan by next Wednesday, or a longer delay if they’re unable to craft a plan immediately. The plan for a so-called Brextension still has to be approved by EU leaders in Brussels. On Thursday, lawmakers overwhelmingly rejected a measure to allow a second people’s referendum on Brexit.

And in Brazil, thousands of people gathered for vigils in cities across the country Thursday to mark the first anniversary of the assassination of Marielle Franco. Franco was a member of Rio de Janeiro’s City Council and a human rights activist who challenged police brutality in one of the world’s most notorious police forces. This week, police arrested two former police officers and charged them with murdering Franco and her driver. This is David Miranda, a federal congressperson from Rio de Janeiro, longtime friend of Marielle Franco and husband of Pulitzer Prize-winning journalist Glenn Greenwald.

David Miranda: “Marielle’s legacy is her struggle, what she did when she was alive. And also, now that she is dead, the legacy goes on. We are the seeds of that legacy, of the fight she took on, of her voice, calling out the genocide of young people in the favelas, the genocide of women, which we are seeing on a daily basis.”