Late last night, L.A. Police Chief Charlie Beck said school district administrators received an email threatening violence against all LAUSD schools.  He said the email mentioned backpacks, explosive devices and assault rifles.

Parents at Campbell Hall, a private school in Studio City, received this email this morning.

Parents at Campbell Hall, a private school in Studio City, received this email this morning.

Police say the email threat was routed through Germany, but they believe the email originated closer to home.

Beck said that after invesitgation by the LAPD, FBI, and ATF and an extensive search of LAUSD schools, authorities have determined that it was not a credible threat.

He said it was very specific to LAUSD schools, and that police do not believe there is a threat to other non-LAUSD schools in the area. Some Catholic schools in L.A. elected to shut down, however, given their proximity to LAUSD schools.

LAUSD Superintendent Ramon Cortines decided to close all schools "out of an abundance of caution."  The district also cancelled its after school programs today.

White House Press Secretary Josh Earnest said this morning that in cases like this, power lies with local authorities.

"Local officials are ultimately responsible for making the decision they believe based on their knowledge of the community makes the most sense and is consistent with their judgment about the best way to protect the community," Earnest said. "And the federal government certainly has a responsibility to support local officials as they make those decisions as they implement them."

LAPD, FBI, and ATF officers have completed their search of school campuses to make sure they are safe. Principals and plant managers were on site to help authorities. L.A. School Police Chief Steve Zipperman said that 2780 officers participated in the search. With the sweep of campuses complete, officials are confident they can safely reopen the schools.

"All of us can go to bed tonight with a lot more comfort knowing that our schools have been checked," Zipperman said in a press conference Tuesday night.

NYPD Police Chief Bill Bratton said that New York schools received a similar threat, but that officials concluded it was not credible.  Chief Bratton criticized LAUSD's decision to close schools, calling it an "overreaction."

Beck defended the decision, saying, "These are tough times. ... Southern California has been through a lot in recent weeks. Should we risk putting our children through the same?'' 

Rep. Adam Schiff, a member of the House Committee On Intelligence, said Tuesday afternoon that authorities are still gathering information, but the threats to L.A. and New York schools are believed to be a hoax, or "something designed to disrupt school districts in large cities.''

Families received a district-wide phone message this morning telling them to keep students at home.  Children that were already on campus were supervised until they could be picked up by a parent or guardian with an ID. The LAUSD said that all students that were on campus have been picked up, and that by noon today there were no longer children on school campuses.

According to the LAPD, this morning in Highland Park a student at Los Angeles International Charter High School was fatally struck by a city-operated truck.  He was walking either to or from school when the accident occurred.  The school is not part of the LAUSD, but it decided to close today.

L.A. Metro services were free until noon for students with an ID, and city parks will remain open until 6:30 p.m.  The Peterson Automotive Museum and DiscoveryCube Los Angeles offered students free admission today.

The LAUSD posted a guide on its website for talking to children about crisis situations.

State Superintendent of Education Tom Torlakson said he supported Cortines' decision to close the schools and he would instruct his staff to work with LAUSD officials to mitigate the drop in funding from the closure.  Schools receive funding from the state based in part on how many students attend class.  A full day of disrtict-wide closure could cost the district nearly $29 million, but Torlakson is certain the district can be refunded.

Senate President Pro Tem Kevin de Leon, D-Los Angeles, said that the Senate would work with LAUSD to ensure the district doesn't lose funding.

"Loss of funding should never be (a) factor in keeping students safe,'' de Leon said via Twitter.

Beck and Zipperman said that all L.A. and school police will be out in uniform tomorrow and school police will increase their presence at schools.

LAUSD is the second-largest in the nation, serving 640,000 students in kindergarten through 12th grade at more than 900 schools and 187 charter schools. 

Video by Helen Zhao and David Merrell. 

Reach Staff Reporter Sam Bergum here. 

This story was originally posted on ATVN.org.