A San Jose family was looking for answers about a fire that occurred at their Willow Glen home Wednesday morning, a day after someone smeared paint on their daughter's car.

"We're certain that the fire was deliberately set," John Unger said after flames damaged the front door and stucco facade of his home in the 1500 block of Glenwood Ave in southwestern San Jose. "There's no question in my mind."

"Someone threw a flammable liquid against my door and set it afire," Unger said. "This was not accidental."

Unger said his wife Janice and 21-year-old daughter Nicole "have no idea, not even a hint of a motive ... why anyone would do something this stupid."

The early morning fire occurred a day after a red Ford Focus used by Nicole was vandalized while it was parked outside the home.

Someone had poured off-white paint over the top and passenger side of the Ford and had sprayed paint on the back of the car, Unger said.

Unger said he was convinced the incidents were related.

"The way they damaged our car, it appeared to be personal," he said.

The blaze, which was reported at 3:09 a.m. today, was isolated to the home's exterior with no interior damage, San Jose fire Capt. Mary Gutierrez said.

The fire department's arson investigators are probing the cause of the fire, Gutierrez said.

San Jose police were working with fire investigators and are also looking into the family's vandalism report, police spokesman Office Albert Morales said.

"So far, there are no suspects and nothing to go on," Morales said.

Unger said he reported the vandalism Tuesday morning after the family woke up and discovered it.

Then, early Wednesday morning, his wife Janice thought she heard a noise outside the home, but he saw nothing from a front window.

Moments later, she heard another noise, and when he peered out the dining room window, he saw flames on his front door.

"I thought I heard something go against the door," he said. I think they drenched my doormat with kerosene or something, then threw it against my door and lit it."

"If we had been solid sleepers, it would have burned my whole house down," Unger said.

After two overnight crimes outside his home in two days, Unger said he is very concerned. 

"I definitely don't feel safe," he said. "The police can't be parking themselves in front of my house. They have so many other things to do."

He said he had the car towed to a paint shop to remove the white paint, and contacted his auto insurance company.

He would have to call his home insurance representative to replace the front door and assess other fire damage, he said.

Unger plans to meet with security professionals soon to determine what he can do to protect his house and property.

"I need to hear what the pros say," he said. 

People living on his block, which is a few blocks east of a church and a synagogue, have told him they are also worried, he said.

"This is a very, very peaceful neighborhood with a clean track record," he said. "That really shakes up the neighbors."