The declaration comes two days after pro-Palestine activists occupied and extensively vandalized the Student Services Building on campus.
"The encampment has crossed a line," Cal State Los Angeles President Berenecea Johnson Eanes said in a statement. "Those in the encampment must leave."
Eanes also said in her statement that four people -- three employees and one student -- were assaulted by protesters during Wednesday's occupation of the Student Services Building, although no other details were released.
Pro-Palestinian protesters barricade building housing president's office at Cal State LA
"A trust we had in the encampment to practice non-violence has been violated," Eanes said in her statement to the "Golden Eagle Community" released Thursday afternoon. "Trust is a hard thing to restore, but we will do the work together."
The protest began Wednesday afternoon as activists descended on the building that houses the university president's office. Some protesters chained themselves together outside the main entrance as others moved inside the building. Others used patio furniture, golf carts and other materials to establish a barricade around the structure. At one point, protesters were seen rolling copy machines in front of the building's entrance.
University officials issued a campus alert urging anyone inside the building to shelter in place, and telling others to leave the campus.
University spokesman Erik Frost Hollins told reporters Thursday that police were able to escort some employees out of the building within a few hours of the occupation beginning. He said, "Obviously it's a different and more dangerous situation when you have people in a multi-story building."
Hollins said Eanes was among about 12 administrators who were initially sheltering in place inside the building.
"There were a dozen, then it got down to maybe half a dozen administrators who remained in the building to work the situation throughout the evening," he said.
Eanes and the remaining administrators left the building shortly after midnight Thursday.
Around 1 a.m. Thursday, most protesters left the building voluntarily and returned to the existing pro-Palestine encampment on the campus. A remaining handful were coaxed out by university officials a short time later.
Pro-Palestinian protesters abandon barricaded building after chaotic night at Cal State LA
A criminal investigation was underway. There were no immediate reports of any arrests stemming from the extensive damage inflicted by protesters, including graffiti on walls and furniture, shattered office windows and overturned vending machines.
A large amount of trash was strewn about in front of the building. The building's first-floor windows and walls were sprayed with pro-Palestinian graffiti.
All classes will meet on a remote basis until further notice, the university announced.
"As you likely know, last night unlawful protesters occupied the first four floors of the Student Services Building, destroying offices, stealing property, and leaving significant damage," Eanes said in her statement Thursday.
"For 40 days, there has been an encampment on our campus. We have been in ongoing formal and informal communication with the encampment and its advisers. I went into the encampment twice. I made significant commitments on transparency, respectful conversations, and mental health support. These are all within my authority and aligned with our first principles as a university."
"So long as the encampment remained non-violent, I was committed that the university would continue to talk."
"Last night, those involved with the encampment chose violence and destruction. Our chief concern at Cal State LA has always been the safety and security of all involved: our students, faculty, staff, public, and protesters."
"Yet, the significant damage to SSB will affect student-facing services: including admissions, records, accessible technology, basic needs, new student and family engagement, Dreamer resources, and educational opportunity programs. It will take time to restore all those spaces and divert significant resources that would otherwise go to academics, student services or operations."
Eanes said she was "saddened" and "angry" about Wednesday's events.
"For all those who sheltered in the Student Services Building, who had to leave in that chaos, thank you for being brave and resilient. Thank you for showing your professionalism and care -- both for each other and for our students. I appreciate your care shown even to those who pursued intimidation and destruction."
"To the three employees and one student whose assaults were reported (one as protesters gained entry to SSB, another as they were leaving, another who was surveying damage, and one accosted on a walkway) I am so sorry. Know that this will not stand."
"Campus community: Know that we will recover from this, but also know that I am committed to doing everything we can to ensure this will never be allowed to repeat. I cannot and would not protect anyone who is directly identified as having participated in last night's illegal activities from being held accountable."
The Cal State Los Angeles chapter of Students for Justice in Palestine wrote on its Instagram page, which has since been taken down, that Eanes "continues to dance around and repress our divestment demands,'' referencing calls for the university to halt any funding or financial support of businesses tied to Israel."
"We've been waiting for a response to our demands for 18 days," according to the group. "There is no more time to spare while families are being massacred by U.S. Imperialism with each minute that passes."
The California State University system "does not intend to alter existing investment policies related to Israel or the Israel-Hamas conflict," according to a statement from the Office of the Chancellor issued April 30.
"Because of state law and CSU's investment policies restrictions, the CSU does not invest in direct stocks or equities in any companies. The system does invest in mutual funds, bonds, and other instruments."
"Through careful management of the university funds, CSU investments provide a stable revenue stream that benefits our students and faculty, and supports our critical campus facilities, scholarships, and other key elements of our educational mission."
"While the CSU affirms the right of our community members to express diverse viewpoints, a divestment of this sort impinges on the academic freedom of our students and faculty and the unfettered exchange of ideas on our campuses."
Police investigators were in the Student Services Building lobby Thursday morning taking full inventory of the acts of vandalism and damage perpetrated by the protesters, the beginning of a criminal investigation.
One student told reporters the protests were getting out of control.
"I just think it's pretty selfish of them," Gilbert Sosa said. "This campus is for everybody. They're just taking over. I don't think it's very appropriate. I don't think they're really accomplishing anything either. I'm here, I'm paying to go to school. I'm here to learn, you know, and I can't today because these guys want to throw a little tantrum."
CSU Chancellor Mildred Garcia also condemned the actions of the protesters.
"What happened at Cal State LA yesterday was unacceptable," Garcia said in a statement. "I want to be clear: The CSU has demonstrated that we value free speech and peaceful protest, but we do not condone unlawful acts that put people at risk. Vandalism, destruction of property, assault, looting are not free speech, they are not protected activities.
"I and my office are in close contact with President Eanes and will be providing her and her team the support they need as they assess the damage that has been done and begin to heal as a community."