A school teacher who was carrying a concealed firearm at school was struck by fragments from a bullet and a porcelain toilet when her gun accidentally fired in a bathroom, officials said.
The teacher was injured when the bullet struck a toilet and caused it to explode, Ben Horsley, spokesman for the school district in Salt Lake City, Utah, said.
Authorities initially thought the teacher had accidentally shot herself. They now believe she was injured when the bullet and toilet fragments struck her lower leg.
The teacher was in good condition yesterday afternoon in a Salt Lake City hospital, Mr Horsley said.
No other staff or students witnessed the shooting, but they might have heard the gunshot or seen the teacher as she was helped out of the school to a waiting ambulance, he said.
Classes continued as usual, and crisis counsellors were available, Mr Horsley said.
Officials were still investigating how the gun discharged. "This just appears at this point in time to be an accident," he said.
Utah is among the few states that allow people with concealed-weapons permits to carry guns in public schools, according to the National Conference of State Legislatures.
Teachers are not required to disclose that they are carrying a weapon, and administrators are prohibited from asking if they carry or barring them from bringing their weapons.
Educators have said they have no way of determining how many Utah teachers are armed, but gun-rights advocates estimated several years ago that 1%, or about 240, teachers in the state are licensed to carry weapons.
The Granite School District requires teachers who carry guns at school to keep the weapons with them at all times, including inside a bathroom stall, Mr Horsley said.