Authorities in Austin believe Willard Wilkerson, 37, started the blaze in May that torched the half of the North Austin duplex he called home — badly burning himself in the process.

Wilkerson faces an arson charge, a first-degree felony punishable with up to life in prison, for allegedly starting the fire that caused $125,000 in damage to the duplex. He was not in the Travis County Jail on Wednesday.

The fire erupted on May 16 shortly after 6 p.m. in the duplex on the 1300 block of Colony Creek Drive, which was home to four — including Wilkerson, his then-girlfriend and her mother.

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Austin Fire Department arson investigators "suspected that the fire was set as part of a suicide attempt, and follow up interviews after the initial investigation confirmed this fact," according to an affidavit to support Wilkerson’s arrest warrant.

The document, made public Wednesday, used statements from Wilkerson, people close to him and a witness to paint a picture of a "drunken and belligerent" man who battled apparent mental issues in the run-up to the blaze. According to his girlfriend’s mother, Wilkerson started the fire "to take us out with him," investigators recounted in the affidavit.

Just minutes before the blaze, the affidavit says, Wilkerson texted his brother-in-law: "I’m lighting myself and everything I’ve worked for." His brother-in-law told Fire Department inspectors that Wilkerson made a series of "bad life choices over the past ten years" and had become "progressively more erratic and self-destructive," the document says.

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Fire investigators said that Wilkerson’s girlfriend showed them a text message he had sent in the fire’s aftermath: "I understand that I did something horrible that hurt you and did a lot of damage."

However, when interviewed at the burn unit of a hospital in San Antonio, investigators wrote that Wilkerson claimed he remembered nothing about the fire or the events that immediately preceded it; he could only recall drinking heavily earlier that day, the affidavit says.

The document also shares other details on the events that surrounded the blaze.

A passer-by saw the blaze and a woman near the front screaming that a man — Wilkerson — was trapped inside. The passer-by said he attempted to get the unit’s front door open, but it was apparently jammed. He yelled inside and heard a male voice reply: "Yeah, I’m in here… Don’t worry about it."

He and two other Good Samaritans went around to the side yard, found Wilkerson face down on a concrete patio in the backyard, dragged him to the curb and handed him off to Austin firefighters, investigators wrote.

Wilkerson was the only person injured in the fire, the affidavit says.