A man has been taken to Nelson Hospital in a critical condition following a crash south of Nelson.
Police were called to the crash around 3.30pm today, which happened on Stock Rd in Golden Downs.
A heavy truck left the road and crashed into a tree, and a man was trapped in the vehicle for a time.
Emergency services cut the man free and he was taken to hospital.
Police said the other occupant was not injured.
The Serious Crash Unit is investigating and traffic control is in place in the area.