Boston - World number one Jason Day's wife and children escaped injury after being involved in a traffic accident, a statement said on Friday.
Day's wife Ellie, children Dash and Lucy and a friend were riding in a car when it was hit by a bus, a statement said.
Ellie Day was taken to hospital as a precaution but later released.
"Thankfully everyone is now resting comfortably," Jason Day said in a statement following his second round at the Deutsche Bank Championship in Norton, Massachusetts.
"We want to thank the emergency services and hospital personnel for their assistance," added Day, who fired a one-under-par 70 at TPC Boston.
In December, Ellie Day was taken to hospital from an NBA game in Cleveland.
She had been sitting courtside when Cavaliers star LeBron James crashed out of bounds while chasing a loose ball. He tumbled into Day, knocked her chair over and landed on top of her.
She was treated for concussion symptoms.