Two people were killed by the attacker, identified as a teenage girl who attended the school.
www.bbc.com
The police chief in the city of Madison said the child who rang 911 just before 11:00 local time (17:00 GMT) was in the
second grade. "Let that soak in for a minute," Shon Barnes told reporters.
Mass shootings are common in the US, including at schools. According to news organisation EducationWeek, 38 of them have caused deaths or injuries this year. There were a total of 69 victims - including 16 deaths - before Monday's attack.