22 children shot dead at Connecticut elementary as 'teacher's son, 24, and second shooter' massacre entire class in worst school shooting in American history!

• At least 29 people are believed to be dead - including 22 children - after a gunman believed to be a teacher's son opened fire today at an elementary school in Connecticut, making it the worst school shooting in U.S. history.

Police were dispatched to Sandy Hook Elementary School in Newtown after they received reports of shots being fired by a gunman in the principal's office and then a kindergarten classrooms at 9.35am.

Sources have named the gunman as 24-year-old Ryan Lanza whose mother is a teacher at the school. 

He is said to have gone from classroom-to-classroom firing at students and teachers with a .223-caliber rifle and specifically targeted his mother's classroom.

His father was found dead at his Hoboken, New Jersey, home around 2pm, according to officials.

Lanza is dead but it is not clear if he shot himself or was brought down by officers.

This is the saddest news ever, 22 innocent young children killed for nothing,...so speechless right now :(