Nuno F.G. Loureiro, a 47-year-old physicist and fusion scientist, was shot Monday night at his home in Brookline, Massachusetts. He died at a local hospital on Tuesday, the Norfolk District Attorney’s Office said in a statement.

The prosecutor’s office said no suspects had been taken into custody as of Tuesday afternoon, and that its investigation was ongoing.

Loureiro, who joined MIT in 2016, was named last year to lead MIT’s Plasma Science and Fusion Center, where he aimed to advance clean energy technology and other research. The center, one of the school’s largest labs, had more than 250 people working across seven buildings when he took the helm.

Loureiro, who was married, grew up in Viseu, in central Portugal, and studied in Lisbon before earning a doctorate in London, according to MIT. He was a researcher at an institute for nuclear fusion in Lisbon before joining MIT, it said.

“He shone a bright light as a mentor, friend, teacher, colleague and leader, and was universally admired for his articulate, compassionate manner,” Dennis Whyte, an engineering professor who previously led MIT’s Plasma Science and Fusion Center, told a campus publication.

The president of MIT, Sally Kornbluth, said in a statement that Loureiro’s death was a “shocking loss.”

The homicide investigation in Brookline comes as police in Providence, Rhode Island, about 50 miles away, continue to search for the gunman who killed two students and injured nine others at Brown University on Saturday. The FBI on Tuesday said it knew of no connection between the crimes.

A 22-year-old student at Boston University who lives near Loureiro’s apartment in Brookline told The Boston Globe she heard three loud noises Monday evening and feared it was gunfire. “I had never heard anything so loud, so I assumed they were gunshots,” Liv Schachner was quoted as saying. “It’s difficult to grasp. It just seems like it keeps happening.”

Some of Loureiro’s students visited his home, an apartment in a three-story brick building, Tuesday afternoon to pay their respects, the Globe reported.

The U.S. ambassador to Portugal, John J. Arrigo, expressed his condolences in an online post that honored Loureiro for his leadership and contributions to science.

“It’s not hyperbole to say MIT is where you go to find solutions to humanity’s biggest problems,” Loureiro said when he was named to lead the plasma science lab last year. “Fusion energy will change the course of human history.”