Bay Space lady suspected of lighting fast-moving Fawn Fireplace close to Redding

A Palo Alto woman was arrested Wednesday on suspicion of starting the Shasta County’s fawn fire, which had grown to 5,500 acres by Thursday evening and triggered mandatory evacuation orders.

The fast moving wildfire burned about five miles northeast of Shasta Lake and was contained 5% by Thursday afternoon.

As firefighters battled the fire Wednesday night, a woman later identified as Alexandra Souverneva, 30, from Palo Alto, left the forest and told firefighters she was dehydrated and in need of medical care, officials said.

After treatment, Souverneva was interviewed by Cal Fire police officers who then arrested her and detained her in the Shasta County Jail, Cal Fire and Shasta County Fire said in a statement.

Witnesses in the area reported that a woman trespassed and behaved irrationally earlier in the day, officials said.

Souverneva, detained on $ 100,000 bail, could face charges of arson in Wildland, officials said.

Residents of the evacuation zones were asked to assemble in the First Church of the Nazarene in Redding.

“Hot, dry conditions and gusty winds cause significant fire growth and rapidly changing conditions,” Cal Fire officials wrote in an incident report released Thursday morning.

At least 25 buildings have burned out and another 2,000 are at risk of fire, according to Cal Fire.

Dominic Fracassa and Andres Picon are contributors to the San Francisco Chronicle. Email: dfracassa@sfchronicle.com, andy.picon@hearst.com Twitter: @dominicfracassa, @andpicon