"In cooperation with the Fairfield Police Department, we began an investigation to determine the origin and credibility of the threat," says Superintendent Pam Conklin of Travis Unified School District.
Conklin wouldn't comment on specifics of the threat, concerned it could jeopardize the investigation, but says they decided to close the school "out an abundance of caution."
RELATED: Police ID 16-year-old killed in shooting near Fairfield high school
It comes three weeks after another incident involving a black student, who was targeted by racial slurs spray painted at the baseball and softball fields and the parking lot of the same school.
The family held a press conference in San Francisco with their lawyer to speak out about the incident.
"We told the principal we wanted those criminals removed from the school because they still had access to our son," says Edward Russell Jr. "They said they can't do that. The students were suspended for five days for vandalism. Not a hate crime. But for vandalism."
Russell says on March 2, his son's name was spray painted on the sports fields along with racial slurs, a swastika and the words "USA for Trump."
RELATED: Controversial history assignment at Arroyo High School asked students to create Nazi time capsule
He says the family met with the superintendent on Tuesday, but that she refused to call this a hate crime.
"For the faculty and the administration to turn their back on my son and his safety, that's a slap in the face to my son," says Russell.
Many parents say they are outraged that district is not being more forthcoming with what's happening at the school.
"Parents need to be notified, as soon as possible. As soon as possible! Not through Facebook. I want a text message. Seriously! This is scary," says Melody Bargon, who lives near the school with her husband and two children.
RELATED: Get help with improving our schools
Joe Gonzalez has similar concerns. He says he's frustrated that his grandson's generation is still dealing with racism on campus, and he's angry that four students involved weren't charged with a hate crime.
"If you give them a week suspension and then let them go back to class, the punishment (doesn't) fit the crime," says Gonzalez.
Fairfield police say they can't comment on an on-going investigation, and because the graffiti incident involves juveniles.
UPDATE 1: Vanden High School in Fairfield closed today due to "threat of violence." School district not releasing any details or nature of the threat, saying it will jeopardize investigation. #whereyoulive #Fairfield #Vacaville https://t.co/YiYU9NiKHe pic.twitter.com/sxeLwlIHs9— Anser Hassan (@AnserHassan) March 27, 2019
UPDATE 2: Superintendent Pam Conklin says not sure of "credibility of the treat" but closed campus "out of abundance of caution." The decision if school will be closed on Thursday will be announced later this evening. #whereyoulive #Fairfield #Vacaville https://t.co/YiYU9NiKHe pic.twitter.com/uXB1RHNEjM— Anser Hassan (@AnserHassan) March 27, 2019
UPDATE 3: 3 weeks ago, Vanden HS was vandalized with #racist #graffiti at ball park and parking lot. Superintendent won't confirm if the incidents are related. #whereyoulive #Fairfield #Vacaville https://t.co/YiYU9NiKHe pic.twitter.com/BNGUV4w6Q8— Anser Hassan (@AnserHassan) March 27, 2019
UPDATE 4: Superintendent Conklin says students in graffiti incident were caught and "appropriate disciplinary action taken." Families involved spoke out today. #whereyoulive #Fairfield #Vacaville https://t.co/YiYU9NiKHe— Anser Hassan (@AnserHassan) March 27, 2019
UPDATE 5: Fairfield PD says they investigated both situations. They can't comment on either because juveniles involved, except that both are on-going investigations.#whereyoulive #Fairfield #Vacaville https://t.co/YiYU9NiKHe pic.twitter.com/gYmqf9GrOl— Anser Hassan (@AnserHassan) March 27, 2019