SAN DIEGO -- In an aerial tour over San Diego, San Diego Fire Chief Tracy Jarman pointed out areas that would be hard to defend in a firestorm -- homes that are in what is known as the ember zone.

Jarman described the ember zone as "embers that are landing on the ornamental, the rain gutters that haven't been cleared, the vegetation that grows over the roof which catches fire and then catches the house."

One particular house in Mission Valley had a lot of green around it, but Jarman said the tree growth was an explosion waiting to happen.

"You should trim any eucalyptus tree limbs that are going over the roof," said Jarman.

Jarman said if you live within 1 mile of a canyon, you are in the ember zone.

With over 900 linear miles of canyon rims in the city alone, Jarman said everybody needs to work together to make their homes fire safe -- and they need to do it now.

"If your home's within 15 feet of another home the chances of that house igniting your house if it catches fire is 100 percent," Jarman said.

If that happens, Jarman said homeowners need to be ready to evacuate.

"You better be set, which means you have the items you want to take with you, whether it's albums or insurance papers," said Jarman.

She pointed to the recent Santa Barbara fire as a prime example of the danger.

"The threat is here. I think you saw it in Santa Barbara. We can clear the 100 feet of defensible space, but it's the ember zones raining down on your neighborhood that ignite the fires," said Jarman.

City code enforcement officers are inspecting properties for fire threat.

If your property is deemed fire unsafe, it could cost as much as $300 in fines unless the problem is fixed.