LOS ANGELES (RNN) - The threat that closed all schools in the Los Angeles Unified School District on Tuesday appears to be a hoax, according to Rep. Adam Schiff (D-CA).
"The preliminary assessment is that it was a hoax or something designed to disrupt school districts in large cities. The investigation is ongoing as to where the threat originated from and who was responsible," Schiff said in a statement to the Los Angels Times.
Los Angeles Mayor Eric Garcetti said threats of violence at all of the district's campuses were made by email Monday night. He said they learned later that other cities, like New York, also received threats. He said the city, police and school officials were working to make sure it was nothing more than a threat.
However, New York City schools did not close down.
Garcetti said Tuesday that officials were acting out of "an abundance of caution" in their investigation of a threat that closed the Los Angeles Unified School District for the day.
"If it had any credibility here or any place in the U.S., especially given what happened in San Bernardino, we wanted to make sure that we supported the school district," Garcetti said.
Los Angeles Police Chief Charlie Beck said the email was very specific to LAUSD campuses and threatened an attack with explosive devices and assault rifles.
The email was routed through Germany, but they believe the origin to be much closer to them, Beck said. The FBI assisted in vetting the threat.
"Any time these threats are made against our campuses, given all the school shootings in America, given San Bernardino, we take them seriously," Beck said. "We gave our school district our best advice on this, and they chose a path."
The LAUSD, one of the nation's largest school systems, closed all its schools after what police called a credible threat. Police were clearing the campuses along with school principals and other staff.
Los Angeles School Police Department Chief Steve K. Zipperman said the threat was made electronically and mentioned the safety of an unspecified number of schools. Officials told the Los Angeles Times the message originated from an IP address in Frankfurt, Germany, and it contained spelling errors.
"Somebody has sent information that leads us to pause and make sure that we are safe, that our children and our staff are safe," said Superintendent Ramon Cortines.
Cortines asked police to search each of the more than 1,000 schools in the district by the end of the day to make sure they were safe.
"I think it is important that I take the precaution based on what has happened recently and what has happened in the past," Cortines said. "I want every school searched to make sure that it is safe for children and safe for staff to be there on Wednesday. I will issue a statement late this afternoon after the chief has informed me that schools have been searched and it is OK."
LAUSD is the second-largest school district in the nation and serves more than 650,000 students from kindergarten through 12th grade. There are 900 public schools, 187 charter schools and more than 27,000 teachers.
Students and staff were directed to stay away from all campuses. This is the last week of school before LAUSD breaks for the holidays on Dec. 18.
"We need families and neighbors to work together with our schools and with our employees to make sure our kids are safe throughout the day," LAUSD President Steve K. Zimmer said. "We need employers to show the flexibility that a situation like this demands; and we ask you to show the maximum possible flexibility with your employees who are primarily mothers, fathers and guardians today in this situation."
Some children were already on buses headed to schools when the call came, and the superintendent expressed concern about students who walk to school and could not be quickly contacted. Teachers and parents were turned away from schools before a districtwide call went out saying schools were closed due to unsafe conditions.
Later on Tuesday morning, New York City Police Commissioner William Bratton said schools in the city received a threat, but the department did not deem it credible. NYPD is investigating the threat with the FBI and a joint terrorism task force as a precaution.
Cortines said Los Angeles schools receive threats "all the time," but he cited nearby San Bernardino and the mood of the country as contributing factors for shutting down the schools.
The mass shooting in San Bernardino, 60 miles from downtown Los Angeles, took place on Dec. 2. Syed Rizwan Farook and his wife, Tashfeen Malik, opened fire on Farook's coworkers at a holiday party, killing 14 and injuring 22.
"It's also the week of Sandy Hook - it's on every teacher's mind," said Vaun Angeline, a Los Angeles schools special education teacher. "No teacher has forgotten."
Monday was the three-year anniversary of the Sandy Hook Elementary School school shooting in Newtown, CT. After killing his mother at their home, Adam Lanza killed 20 students and six staff members on the campus, making it the deadliest mass shooting at a primary or secondary school in the country's history.