Austin Fire crews at the scene of a fire at a south Austin complex. (KXAN: Todd Bailey)

AUSTIN (KXAN) — Investigators believe a woman’s anger at her partner being romantically involved with a man led to a fire in south Austin that ultimately left 19 people without homes.

Richelle Williams, 26, faces an arson charge, which is a first-degree felony. Police say she lived at the apartments on 9903 Roxanna Drive, north of Slaughter Lane, with her girlfriend. Previously, Williams had called police about a man who they say turned out to be “romantically involved” with Williams’ girlfriend. Williams and the man had fought about the relationship, according to an affidavit.

Williams’ girlfriend reached out to KXAN Tuesday in support of Williams and said the fire “didn’t start in her apartment.”

Related Headlines South Austin blaze classified as arson, 19 people displaced

“I know without a reasonable doubt that Richelle Williams wouldn’t do that,” Williams’ girlfriend said.

Investigators found the fire had started in two separate closets in Williams’ apartment. Williams said she discovered the fire in an outdoor storage closet and attempted to extinguish the fire, according to the affidavit.

On Friday, firefighters rushed to the apartment complex at 3:28 a.m. to put out the fire at the four-plex apartment.

“The staircase to the second floor apartments was on fire, and tenants, including three children, had to be rescued from the balcony,” the affidavit said.

The damage was estimated to be $150,000 for the structure and $50,000 for the contents.

Williams is not currently listed as being in custody.