Hofstra University student Andrea Rebello was killed Friday after a gunman broke into her off-campus home, took her hostage, then got into a shoot-out with responding police officers.

It’s unclear whether the 21-year-old native of Tarrytown, N.Y., was killed by the gunman or police who were shooting at the  intruder, who was also killed during the gunfight, the New York Times reported. Rebello’s twin sister, Jessica Rebello, whom the gunman had allowed to leave the Uniondale home to withdraw money, was not hurt in the incident.

Hofstra University President Stuart Rabinowitz said in a statement posted on the school’s website that Rebello had been killed but said the Hempstead, N.Y.-based university did “not yet know all of the relevant details” of the student’s death.

“The Nassau County Police have notified us that early this morning a Hofstra student, Andrea Rebello, a junior majoring in public relations, was killed during a tragic crime that took place in a rental house off campus,” Rabinowitz said. “The police investigation is ongoing, and we do not yet know all of the relevant details. What we do know is that a young member of the Hofstra family has been taken from us in a senseless act of violence. Our hearts and minds and our thoughts and prayers are with her family, her friends and her classmates. While our hearts are laden with grief, this weekend’s commencement ceremonies will go on as scheduled. The accomplishments of our graduates must be recognized, and together our community will heal and find the strength to move forward.”

The gunman forced his way into the home in Uniondale, N.Y., around 2:15 a.m. Friday, the Times reported. He was wearing a ski mask and carrying a gun.

The suspect took Rebello, her twin sister and a male roommate hostage before letting the sister leave so she could withdraw money, the Nassau County Police Department on Long Island told the Times.

Subsequently, the sister called 911 and reported that a gunman broke into the home and was holding hostages. Police responded minutes after the call.

“Shortly after our arrival, a shooting took place where the suspect is killed and one of the female victims is killed,” Nassau County Deputy Inspector Kenneth Lack told the paper.

Victoria Dehel, a Hofstra student who lived near Rebello, described the sounds she heard emanating from the home where Rebello was killed.

“It was about two in the morning and things were normal and all of a sudden you hear a girl screaming and a guy screaming after her. It was just awful,” Dehel told New York television channel WPIX 11.

Dehel also spoke to the Times about what she heard.

“I was with my boyfriend, and we were just listening,” she said. “And then the screaming just got worse and worse and worse. And then we heard thuds, like five bangs. Me and my boyfriend went on the porch to see what was going on. And we saw cops flying down the block.”

The circumstances of the shooting are being analyzed, John Capece, Nassau County chief of detectives, told the Times, noting, “We are going to get to the bottom of what happened.”