All that's left of this California mom's house are these blocks with handprints

"We're safe, we're healthy," she said. "It's only stuff for the most part."

— -- As deadly wildfires continue to ravage Northern California, a single mom is now being forced to start over after her entire home was incinerated.

Lisa Wahnon described evacuating her Santa Rosa home of eight years with her only son, Ben, as "crazy and chaotic."

"The power went out and we heard a bunch of commotion outside. We looked outside and there's a whole bunch of cars lining up in the street to leave," she told ABC News. "We just got a couple things and walked out."

She said she had to stay calm to get out. "I had to be a mom," she said. "I had no choice."

In Sonoma County, where Santa Rosa is located, 27,000 acres have burned and at least nine people have died. The Sonoma County Sheriff's Department says it has 155 unresolved missing person reports. All Sonoma County public schools are closed today and officials say 24 evacuation centers are open to the public. Overall, there have been at least 15 wildfire-related deaths in the state.

Wahnon said she came back home after evacuating because she "had to see for myself" what was still there.

The house was no longer standing, and nearly all of their possessions had been incinerated, including her son's baby blankets and clothes and Christmas stocking, and her father's photos and Purple Heart and Medal of Honor from Vietnam.

The one thing that survived was concrete blocks she and her son made with handprints when they moved in in 2009. Ben was 6 years old at the time.

"It was like the christening of our house," Wahnon said.

With only the clothes on their backs, Wahnon said she isn't sure what they will do going forward.

"Have a big cry. Figure out what we're gonna do," she said. "Try to rebuild our life."

For now, she is staying with her friend, also a single mom and nurse.

"We're safe, we're healthy," she said. "It's only stuff for the most part, right?"

ABC News' Matt Gutman and Scott Shulman contributed to this report.