Boy aged three dies in NSW car crash

A three-year-old boy has died after the car he was in left the road and crashed into a tree at Mulwala in NSW's southwest.

Following the crash at about 4pm on Sunday a four-year-old boy was taken to Albury Hospital in a serious but stable condition and the driver, a 40-year-old man, was airlifted to Melbourne Hospital for treatment, police said.

At around 10am on Sunday a Sydney man aged in his 50s died after crashing his motorcycle into a tree at Bell near Lithgow in the Blue Mountains.