A law student huddled in the Student Union at Florida State University during a shooting allegedly killed 17 people on December 21, 2018, a day after the Orlando State shooting

In an alert to those on campus shortly after noon, FSU warned people to “shelter in place” and that police had responded to “an active shooter call at the Student Union.”

The President said he had been briefed. “It’s a horrible thing. It’s terrible that things like this happen.

FSU canceled all classes and business operations until Friday after telling students to avoid the campus. The university said later it’s canceling all “athletics home events” through Sunday.

Florida State University is one of the oldest and most recognized universities in the state. More than 16,000 employees, faculty, and staff work on the campus.

In addition, the fear for the students who sheltered in place at Florida State University was linked to the school shooting in Florida in which 17 people were killed.

Joshua Gallagher, a law student at Florida State who went to Marjory Stoneman Douglas High School in Parkland, wrote on social media on Thursday that he never thought that gun violence would hit close to home again.

“Then I’m in the FSU Law Library,” where he heard an alarm: “active shooter on campus,” Mr. Gallagher wrote on X. “No matter your politics, we need to meet — and something has to change.”

Ilana Badiner, 21, who is graduating from Florida State in two weeks, said in an interview that she huddled in the student union basement with about 30 people during the shooting. In 2018, she was a student at a school adjacent to Marjory Stoneman Douglas High School. She said her school was on lock down for four hours.

The Parkland shooting massacre: Why there is so many guns in our society, why we don’t have them anymore, but we can do better

There was a lot of crying today, like the same situation where people were just on the phone. “It’s terrible that this keeps happening.”

There were 17 people killed at the high school in the city of Parkland when a man, armed with a semiautomatic rifle and 300 rounds of magazine, went on a rampage in a freshman building. There were three faculty members and 14 students. Another 17 people were injured in the shooting, one of the deadliest in American history, which fueled continuing calls for tougher gun control measures.

Fred Guttenberg, a vocal critic of existing gun laws who lost his 14-year-old daughter, Jaime, in the Parkland massacre, condemned what he said had been a lack of progress to prevent more shootings.

The co-chairs of March for Our Lives, a group led by students who survived the massacre at the school, echoed Mr. Guttenberg’s criticism.