WHAT SHOULD I DO WHNE MY 8 YEAR OLD SAYS IN SCHOOL HE WISHES HE WERE DEAD

My 8 yr old got a time out in school today,an he told his teachers he wishes he were dead!? he has never talked like that at home!!! where did this come from and why would he say that!!!
I just had a daughter 3 months ago would that make him angry or bitter because he was the only child for so long!!??