The Los Angeles Unified School District took the unprecedented step Tuesday of closing all of its schools due to an emailed threat that was later deemed a hoax, less than two weeks after a shooting in nearby San Bernardino left 14 dead and a nation on edge.

The email sent to officials on Monday night said multiple, unspecified schools would be targeted in an attack with guns and explosives, Los Angeles Police Department Chief Charlie Beck said. Later on Tuesday, the House Intelligence Committee said that the threat was not credible.

New York officials received a similar threat on Monday and said it was a hoax .

The decision by Los Angeles authorities to close 900 schools and 187 public charter schools as a precaution was swiftly criticized.

New York Police Commissioner William Bratton appeared to disagree with the move , saying, To disrupt the daily school schedules of half a million school children, their parents, daycare, buses, based on an anonymous email with no consultation -- if, in fact, consultation did not occur with law enforcement authorities -- I think it was a significant overreaction.

Yet district Superintendent Ramon Cortines repeatedly defended the decision, citing the San Bernardino attack.

"Its due to circumstances in neighboring San Bernardino I as superintendent am not going to take the chance with the life of a student," Cortines said. He called the email a "rare threat."

Beck said Los Angeles officials began to work jointly to vet that threat after they received it on Monday. He added it was irresponsible to criticize the school closures at that point.

Rene Alexander said his 13-year-old niece was on the bus to Thomas Starr King Middle School when he got an automated call at 7:15 a.m. saying schools were closed.

Thats when the panic set in.

I was saying, what do I do? What happens when she gets to school? I was shaking -- in absolute fear, he told The Huffington Post.

Alexander said he was grateful for the district's message, but didnt get enough information about how to pick up his child or what was happening. He said he had to Google all the information and wondered whether it was a bomb threat or something else.

"I wont be calm until shes with me," he said. "Look, you cant rely on the school system. They cant protect every one of those kids."

After the decision to close the schools, Cortines said he notified principals to set up meeting areas at their respective schools for students and parents, according to CBS Los Angeles .

"Were making every effort to see that we get the notification to parents as soon as possible," Cortines said. "But I am not taking the chance of bringing children any place, into any part of the building, until I know it's safe.