ALDEN — Alden-Conger School Superintendent Joe Guanella said classes went smoothly at the school Monday with numerous officers and staff monitoring students throughout the day.

Guanella said despite a threat found written at the school last week, nearly 80 percent of the students came to school Monday, and things were quiet all day.

Student movement for sixth- through 12th-graders during the school day was greatly reduced and tightly supervised, while the younger students, age kindergarten through fifth grade, had a nearly normal day.

He said the school will continue the law enforcement presence and control the movement of the sixth- through 12th-graders until conditions warrant a change.

“Law enforcement continues to work on finding the person responsible,” Guanella said.

He thanked the Alden Police Department and Freeborn County Sheriff’s Office, which offered assistance after the incident.