(NBC News) – Sandy Hook Elementary School in Connecticut, was evacuated Friday morning after receiving a bomb threat on the sixth anniversary of the mass shooting that left 26 students and teachers dead.
Newtown Police Department said it received a call around 9 a.m. ET that a bomb was at the school. Officers were sent to the school and conducted a search as a precaution, but do not believe the threat was credible. The school was evacuated as a precaution and students were sent home for the day.
On Dec. 14, 2012, 20 first-grade students and six educators were killed at Sandy Hook by gunman Adam Lanza. He had shot and killed his mother, Nancy Lanza, before going to the school and opening fire. He shot himself as police closed in.
The threat comes one day after police departments across the country and in Canada were alerted to bomb threats sent to businesses, hospitals and other places. Authorities in both countries said the reported threats were either emailed or phoned in.
On Friday morning, the Detroit Police Department said in a series of tweets that it was investigating multiple threats targeting two courthouses in the city and three hospitals.
“At this time it is believed that these threats were received by phone,” the department said, later adding that the department’s bomb squad investigated four of the locations and did not find any explosive devices.