Fire that caused about $1.5 million in damage at a western Wisconsin elementary school earlier this week was purposely set, federal authorities said Thursday.

The torching of St. Croix Central Elementary School in Roberts about 3:45 a.m. Tuesday "was an attack on a public institution that displaced hundreds of students and educators for the remainder of the school year," said Scott Sweetow, St. Paul's special agent in charge of the federal Bureau of Alcohol, Tobacco and Firearms (ATF).

"Destruction of public property by arson is a particularly cowardly violent crime," Sweetow added, "and I will make sure that all of ATF's resources are made available throughout this investigation."

ATF spokesman Robert Schmidt said there was evidence of forced entry in connection with the fire. He declined to elaborate on the investigation.

The ATF is offering a reward of up to $5,000 for information that leads to an arrest in the case. Tips are being fielded by the St. Croix County Sheriff's Office at 1-715-386-4701 and the ATF at 1-608-441-5050.

The fire was centered on the front of the school, at 202 S. Division St., severely damaging the offices and library, according to police. The blaze was contained in less than two hours.

Instruction for the rest of the week for the 600 or so students was called off. Administrators are planning to resume classes Monday at the Rolling Ridges Girl Scout Camp, 4 miles west of Roberts.

Paul Walsh