People who live near Los Angeles are understandably still worried about terrorism threats. The December shooting that killed 14 people happened in San Bernardino, only 96 kilometers away.

Today, the Los Angeles Unified School District closed all of its campuses after a terrorist threat was delivered via e-mail to some school board members. The threat was not real. But as a precaution, the school district asked that 700,000 students not come to school. The Twitter hashtag #LAUSD was used 50,000 times on Tuesday. Similar threats were sent to school administrators in New York City, but schools were not closed there. The closing proved to be a disruption for parents. They had to care for their children on an unscheduled day off. But most parents seemed to be supportive of the decision.