But all the students were evacuated from the building and then dismissed for the day after the threat was discovered at about 9:30 a.m. Monday, Trooper First Class Kelly Grant said.
State Police investigated and searched the entire school, which is located on Hayestown Avenue in Danbury, Grant said. "Investigation [completed] by troopers and search by K9 teams," she said via email at about noon. "Students dismissed. Troopers have cleared from the school."
No injuries were reported in the incident, Danbury police said.
At about 9:30 a.m., state troopers and the Danbury Fire Department responded to the state-run high school.
The State Police Emergency Services Unit was on the scene, assisting with the investigation, Grant said.
The nearby Hayestown Elementary School had also been on a soft lockdown, Mayor Mark Boughton said.
Parents were told to pick up students from the nearby ShopRite parking lot, WLAD-AM said.
Abbott Tech is located on Hayetown Avenue, with the elementary school next door at the intersection with Tamarack Avenue. No roads were closed, but police report an increase in traffic in the already busy area near the North Street retail area off Exit 6 of I-84.
Click here to follow Daily Voice Danbury and receive free news updates.