What to do/say to DS he is cursing, threatening at school

[Guest guest]

I,

I'm at a loss here. My DS is 11 and he is having " putburst " at school.

Cursing, having discussing regarding violence and weapons, talking about

stabbing. He does not do this at home.....how does one address this with their

child.

The school does not see him as a threat, but he can's say things like that

I'm looking for advice. When I got the note I wanted to cry

Thanks

bobbie