Honduran authorities have arrested four men in connection with the murder of environmentalist Berta Cáceres. Cáceres was gunned down in her hometown of La Esperanza last month. For a decade, she led the struggle against the Agua Zarca Dam, planned along a river sacred to her people, the Lenca. Last year she won the prestigious Goldman Environmental Prize. She had faced repeated threats. Honduran President Juan Orlando Hernández hailed the arrests.

President Juan Orlando Hernández: “The authorities have captured four suspects in the death of our fellow citizen Berta Cáceres. When this happened, we said this was a hit on the Honduran state. And I repeat it again. Taking the life of Berta Cáceres is a hit on the Honduran state.”

The suspects include Sergio Rodríguez Orellana, a manager for social and environmental issues for DESA, the company building the Agua Zarca Dam, and Douglas Geovanny Bustillo, who has worked for a security firm hired by the dam project. The other two are reportedly a Honduran army major and retired captain. Berta Cáceres’ family has called for an independent investigation, saying they have been excluded from the Honduran government’s probe. In a statement, the family said: “Because we have been denied our right under Honduran law to participate in the investigative process from the beginning, we have no way of knowing if these arrests are the product of an exhaustive and diligent investigation, nor do we know if they include those who ordered the assassination. The news of the alleged participation of active and retired members of the military linked to DESA in the assassination should be investigated further and indicates involvement by state agents which is enough reason for the immediate suspension of and a definitive end to the Agua Zarca hydroelectric project.”

Indiana voters head to the polls today in a primary contest seen as pivotal for Republican front-runner Donald Trump’s path to the nomination. Texas Senator Ted Cruz has sought to derail Trump’s lead in Indiana. Campaigning in Marion alongside Indiana Governor Mike Pence, Cruz confronted a Trump supporter.

Sen. Ted Cruz: “America is a better country…”

Trump supporter: “Without you.”

Sen. Ted Cruz: “Thank you for those kind sentiments. Let me point out, I have treated you respectfully the entire time, and a question that everyone here should ask…”

Trump supporter: “Are you Canadian? Are you Canadian?”

Ohio Governor John Kasich backed off campaigning in Indiana under a deal with Cruz aimed at blocking Trump’s nomination. Meanwhile, polls show Hillary Clinton and Bernie Sanders in a close race in Indiana. Campaigning in Kentucky Monday, Clinton said she would put her husband, former President Bill Clinton, to work on her jobs plan.

Hillary Clinton: “I’ve told my husband he’s got to come out of retirement and be in charge of this, because, you know, he’s got more ideas a minute than anybody I know. You’ve got to put people back to work and make it—make it happen.”

In Detroit, Michigan, all but three of the city’s 97 public schools shut down Monday after teachers called out sick to protest funding shortfalls. The teachers learned over the weekend the district is set to run out of money on June 30, meaning the teachers may not be paid. More than half of Detroit’s schools are closed again today as the protests continue. Ivy Bailey, interim president of the Detroit Federation of Teachers, said in a statement: “There’s a basic agreement in America: When you put in a day’s work, you’ll receive a day’s pay. [Detroit Public Schools] is breaking that deal.”

In Iraq, a car bomb exploded in the Iraqi capital Baghdad Monday, killing at least 18 Shiite pilgrims and wounding 45 people. The attack came a day after two car bombs in the southern city of Samawah killed at least 31 people. ISIS claimed responsibility for both attacks.

The White House has called for Congress to take urgent action on Puerto Rico’s debt crisis as the island defaulted on the bulk of a $422 million debt payment. White House Press Secretary Josh Earnest spoke Monday.

Josh Earnest: “The situation gets worse by the day. And in some days, in some situations, the—in some days, the situation gets notably worse. And it only makes a bailout more likely, which is why, you know, we continue to press hard for Republicans in Congress to stop dragging their feet and to address a situation that’s having a negative impact on more than 3 million Americans who live in Puerto Rico.”

Monday’s default represents only a fraction of Puerto Rico’s $70 billion debt. Puerto Rican Governor Alejandro García Padilla echoed calls for congressional action.

Gov. Alejandro García Padilla: “We are going to end up in the hands of judges, both from here and from outside, federal and local judges, from Puerto Rico or from other parts of the United States. Recently, we had a federal judge that upon the choice of giving $115 million to Puerto Rico or to Wal-Mart, he opted for Wal-Mart. We are at the mercy of that type of decision. Congress needs to act.”

The thawing ties between Cuba and the United States have reached a new commercial milestone. A Carnival cruise ship sailed into port in Havana after departing Miami, becoming the first U.S. cruise ship to reach Cuba in half a century. About 700 people were on board, many of them Cuban Americans returning for the first time in decades.

The United States has signed a new agreement with the West African nation of Senegal to allow easier deployment of U.S. troops there. The deal appears to be the first of its kind in the sub-Saharan region amidst an ongoing U.S. military expansion in Africa.

A Somali refugee has set herself on fire on the Pacific island of Nauru, where Australia sends asylum seekers who try to reach its shores by boat. It’s the second time within a week a refugee has self-immolated on the island. On Wednesday a 23-year-old Iranian man, Omid Masoumali, set himself on fire to protest conditions and Australian immigration policies. His wife said he went two hours without medical care. He died Friday. The 21-year-old Somali refugee, identified only as Hodan, is undergoing treatment.

The Israeli military has ordered a Palestinian journalist to be held for four months without charge or trial. Omar Nazzal is a leading member of the Palestinian journalists’ union. Israeli authorities have claimed he is a member of the Popular Front for the Liberation of Palestine, which Israel deems a terrorist group. But his attorney says he is being targeted for his activism.

The Colorado Supreme Court has blocked cities from imposing local bans on the oil and gas drilling process known as fracking. The court struck down a five-year fracking moratorium passed by the city of Fort Collins, saying it was trumped by state authority to promote industry.

Greenpeace has called for a halt in secret U.S.-European Union negotations over the massive TTIP trade deal. Greenpeace made the call after leaking documents it says show how the U.S. is pressuring European countries to loosen environmental and consumer protections. Stefan Krug of Greenpeace spoke out.

Stefan Krug: “We are quite sure, and the text now confirmed that, that if the TTIP in its present form would become reality, that would result in a severe downshift of standards in Europe, on the environmental side, but also on the consumer side. It is quite clear that the Americans have a complete different philosophy of protecting the environment and the consumers. So I guess it’s a good moment to try to put transparency into this whole process and to really start a public debate about it.”

An abortion provider has filed a federal civil rights complaint, saying the Washington, D.C., hospital where she works forbade her from speaking out in support of abortion rights. Dr. Diane Horvath-Cosper accused officials with the MedStar Washington Hospital Center of imposing a “gag order” against her pro-choice advocacy. Following an attack by an anti-choice extremist on a Colorado Springs Planned Parenthood, the hospital’s medical director told Dr. Horvath-Cosper he “[did] not want to put a Kmart blue-light special on the fact that we provide abortions at MedStar.”

The Justice Department says South Dakota has violated federal law by holding thousands of people in restrictive group homes unnecessarily. An investigation found people with disabilities, mental illness or diabetes are warehoused in nursing homes or long-term care facilities, even though many are capable of living at home.

An animal rights activist has been sentenced to two years in prison on accusations of freeing mink from fur farms and vandalizing property linked to the fur and meat industries. Joseph Buddenberg had been charged under the Animal Enterprise Terrorism Act, a 2006 law that elevates crimes like vandalism to terrorist offenses if they threaten industry profits.

In other animal rights news, the elephants of the Ringling Bros. and Barnum & Bailey Circus have performed their last show. The circus announced last year it would end its elephant acts amid mounting public concern over animal mistreatment. The elephants are headed to a refuge in Florida, where the company that runs the circus is based. Humane Society CEO Wayne Pacelle told NPR the decision to end the Ringling Bros. elephant acts was “almost like the [fall of] the Berlin Wall within the animal welfare [community].”

And the photographer and activist Bob Fitch has died at the age of 76. Fitch was known for his iconic photos of the civil rights and farmworker movements. He served as a staff photographer for Rev. Martin Luther King Jr.'s Southern Christian Leadership Conference and later followed Cesar Chavez and the United Farm Workers union. His photograph of Cesar Chavez became a postage stamp, but Fitch was disappointed the U.S. Postal Service removed the original background of the red-and-black UFW flag and replaced it with an image of a field. Fitch also captured photographs of Catholic Worker founder Dorothy Day, Joan Baez and an iconic image of legendary pacifist poet and priest Daniel Berrigan flashing the peace sign while in handcuffs. Father Dan Berrigan died Saturday. Fitch died Friday in Watsonville, California, after a battle with Parkinson's disease.