A home being built for the son of Jack Nicklaus in Jupiter, Florida, has been destroyed by fire.

The fire started early Wednesday at the home of 39-year-old Gary Nicklaus. A former PGA golfer himself, Nicklaus had filed for building permits in January at the Bears Club, a golf community developed by his father.

The second floor of Gary Nicklaus’ home was almost finished when the fire started about 5 a.m. Palm Beach County Fire Rescue spokesman Capt. Don DeLucia said the cost of the damage was unclear but that construction would have to restart from scratch. The cause of the fire was under investigation.