The entire Los Angeles Unified School District was closed today after reports of an unspecified threat.
Details of the threat were filtering in quickly on Tuesday morning. Police confirmed that the threat had been received "electronically," but authorities have not yet made clear to whom the threat was addressed.
School Superintendent Ramon C. Cortines spoke to reporters to explain the closure.
"This morning, at just after 5 am, I received a phone message from [LA School Police] Chief Zipperman… and he shared with me the threat that had been made to not just one school, but many schools in this district — he shared with me that some of the details talked about backpacks, talked about other packages," he said. " After... talking with him, also with the board president, I made a decision to close all of the schools."
"We get threats all the time," he added. "This was a rare threat."
Cortines wants to have all of the district's more than 900 schools searched before they are re-opened. The district is the second largest in the country, with over 655,000 students and 31,000 teachers.
"I received a text from another mom and called the principal to confirm. School's out," said a parent whose son goes to Mid City's Prescott School of Enriched Sciences, who requested to not be identified.
"Right now, we ask parents and families: if you have not yet sent your children to school, please do not send them to school," said Steve Zimmer, the school board president. "We need the cooperation of the whole of Los Angeles today. We need families and neighbors to work together with our schools and our employees to make sure our kids are safe throughout the day. 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 and fathers and guardians today — in this situation."
The FBI is reportedly assisting police in the investigation, according to CBS News. The threat was made less than two weeks after a radicalized couple killed 14 people in a shooting in nearby San Bernardino.
Later, New York Mayor Bill de Blasio and the New York Police Department confirmed they had received a similar threat but had decided it was not credible.
"Our schools are safe. Kids should be in school today," the mayor said. "We will be vigilant. But we are absolutely convinced our schools are safe."
Speaking to the press on Tuesday, de Blasio and NYPD police commissioner Bill Bratton, who was previously chief of the Los Angeles Police Department, also implied that Los Angeles officials had overreacted to the threat.
"Based on the information that we have, this was a very generic piece of writing sent to a number of different places simultaneously and also written in a fashion that suggests that it's not plausible," the mayor said. "In fact, it's very important not to overreact in situations like this."
One thing that suggested to authorities that the threat wasn't credible, Bratton said, was that the email did not capitalize "Allah," the Arabic word for god.
"The language in the email would lead us to believe that this is not a jihadist initiative," he remarked. "That would be incredible to think that any jihadist would not spell Allah with a capital 'A.' "
Bratton neglected to note that there is no capitalization in the Arabic language.
Law enforcement sources told NBC4 News that the email threat was received at 10:15pm PT on Monday, and revealed that a trace indicated that the IP address was based in Germany. It is not clear whether authorities have determined if the German IP address might have been used as a proxy for a sender based elsewhere.