Son feeling suicidal

Feeling quite lost.. my 6 year old son told his teacher that he wants to kill himself then told the counselor he would do it by stabbing himself in the stomach...

We don’t know what to say to him.

We’re confused as to how he understands the meaning of the words well enough to have formed a plan.

We’re very concerned and have started by calling the counseling center for children but we know that won’t be enough to help him feel fully supported.

Any advice is welcome but please hold the negative feedback. This is new for us.