According to NBC News: An 11-year-old boy was arrested after bringing 400 rounds of ammunition, several knives and a handgun to school on Wednesday, police said.

Frontier Middle School, in Vancouver, Wash., was locked down for about two hours after ammunition was found at around 9:20 a.m. local time (12:20 p.m. ET).
The student was interviewed by detectives and later arrested on a count of attempted murder, police said. No injuries were reported.

The boy was booked into Clark County Juvenile Detention Center later Wednesday.
Both the middle school and the adjacent Pioneer Elementary School were put on lockdown, The Columbian newspaper reported.

Police spokeswoman Kim Kapp told the newspaper that investigators with the Major Crimes Unit started conducting interviews at 11:30 a.m. (2:30 p.m. ET) and these went on well into the night.

There are an estimated 900 students at Frontier Middle School and 600 at Pioneer Elementary School, according to The Columbian.

You can imagine what an 11yrs old boy will do with this weapons...