More than 100 firefighters worked to extinguish the blaze and protect the surrounding neighborhood.
"We went quickly into a defensive mode because of the fully involved structure and then went to protect the surrounding houses," explained Asst. Chief David Almaguer with the Houston Fire Department. "That's why it went to a third alarm, to get enough manpower to protect all the surrounding houses."
One person at a garage apartment on the property at the time the fire broke out called 911 and escaped unharmed. One firefighters suffered minor burns to his foot.
Neighbors grabbed what belongings they could and evacuated their homes with family members, terrified as high winds blew hot embers toward their homes and park filled with dry trees.
"It was the sound of things popping and stuff that doesn't happen at 4 in the morning," said neighbor Ethan Ekici. "There were no alarms actually."
"At 3:45 I started hearing sirens and explosions. I heard about three," said neighbor Joi Moore. "We could hear embers falling and they were traveling over the park near the houses."
The fire broke out at about 3:45am at a home neighbors tell us is worth $2 million and is the largest home in the Heights at about 9,000 square feet. The Queen Anne style showplace home said to be owned by doll collector Patty Worthington is often opened to visitors.
"It'll be sad to see it come down," said Ekici. "It was just built maybe three or four years ago."
Telephone poles also caught fire in the massive blaze and power was knocked out to several nearby streets.
Arson investigators are on the scene. No cause for the fire has yet been determined.
Stay with ABC13 Eyewitness News for the latest on this developing situation.