SAN ANDREAS, Calif. (AP) -- A pipe bomb explosion at a county government building damaged part of the structure that houses the jail, the courthouse and other offices but no one was hurt, sheriff's officials said.
Although there were no injuries, Monday's explosion in the Calaveras County seat building knocked a janitor off his feet, said Capt. Mike Walker.
``It was large. It was very large,'' Walker said of the explosion.
A California Highway Patrol officer who first heard the blast saw smoke as he was leaving the county jail and called firefighters to the scene. No evacuation of the surrounding area was necessary but local officials kept a distance at first thinking there may have been more than one explosive.
``We were concerned about there being a secondary device so the units were backed out of the immediate area,'' Walker said.
State fire marshals and investigators from the Bureau of Alcohol, Tobacco and Firearms are sifting through the cordoned off building Tuesday for additional explosives and clues about the cause of the blast, Walker said.
