A fire broke out in a building covering a hot tub at a home in the hills north of Windsor on Friday night.
Several engines responded to the fire near the top of Brooks Road, a narrow winding road extending 3 miles north of Arata Lane.
Cameron Goetzell, 26, said the fire destroyed the 12-by-12 redwood structure beside his grandfather's home.
"It looked like a sunrise. It was just like a big orange cloud," Goetzell said.
Goetzell said he woke up his grandfather, called 911 and then sprayed the fire and house with a garden hose until firefighters arrived.
He said he had no idea what caused the fire, which spread to a woodpile, fence and nearby trees.
Dispatchers said the blaze was contained at about 9:43 p.m. Fire crews remained on the scene late Friday and were unavailable to provide details.