On January 19, a high school in Gardiner, Maine, received a message saying there was a bomb inside the school and a shooting was imminent. That day in Millsboro, Delaware, a caller claimed to be armed and on the roof of an elementary school, threatening to injure students and staff. In Wellington, Florida, a threat of a shooting was found on a sign at Palm Beach Central high school—the third threat on Palm Beach County schools in just over a week.

That was only a portion of the dozens of threats against schools that day, including those targeting nearly 30 schools in New Jersey. Amid an atmosphere of insecurity from a bad year of mass shootings in 2015, a wave of violent threats has hit schools across the nation. A series of bomb threats disrupted Ohio schools last fall, drawing attention from the Department of Homeland Security. And in December, threats resulted in a shutdown of all 900 schools in the Los Angeles Unified School District, with the region still on edge after the San Bernardino massacre. (Similar threats to New York City schools the same day were deemed less worrisome and drew a different response.)

Schools Across America Are Facing a Rash of Shooting and Bomb Threats