A woman and a boy have been killed and a man is in a serious condition after a car crashed into a tree.
Ambulance crews were called to the collision in Crimplesham, Norfolk, just after 7.30am on Sunday morning but the woman - believed to be aged in her 20s - was pronounced dead at the scene.
A boy, thought to be aged between 14 months and three, later died at Queen Elizabeth Hospital in King's Lynn, while the gold 318 BMW's male driver, believed to be 30, was flown to Addenbrooke's Hospital in Cambridge in a "critical" condition.
Police said they believe the victims are Eastern European nationals local to the East Anglia area.
A spokeswoman for the East of England Ambulance Service NHS Trust described the incident as "incredibly tragic".
"Our thoughts are with all those affected," she added.
Meanwhile, a man has died in hospital after the black Ariel Atom high performance sports car he was travelling in as a passenger hit a tree near Sevenoaks, Kent, on September 15.