Update: 6:55 p.m.
Police are looking for a 16-year-old boy who was showing a gun that went off and wounded another teen on a city bus in Monona.
WISC-TV says the victim, a 17-year-old, was shot in the leg and is suffering from non-life-threatening injuries. Police believe both the victim and the shooter to know each other, but it's unclear if the shooting was intentional or an accident.
After a day in metropolitan Madison involving a shooting at an area business with the suspect dead and four others injured, there is a report of a shooting on a city bus in that area.
WISC-TV says that police in Madison took a call just before 4 p.m. about someone being shot on a bus in Monona.
One person has been hospitalized.
According to the report, La Follette High School, Monona Grove High Schools and a middle school in the area are on lockdown.
Check back for more details on this breaking story as they come in to us.