Thecause of death for Mary Jane Thomas, the wife of country singerHank Williams Jr., has been revealed.

The autopsy lists the cause of death as “pneumothorax due to perforated parietal pleura during liposuction with autologous fat reinjection procedure.”

Hank Williams Jr. and Mary Jane Thomas in 2002.Frank Mullen/WireImage

Hank Williams Jr. and wife Mary Jane

A representative for Bafitis Plastic Surgery did not immediately respond to PEOPLE’s request for comment, nor did a spokesperson for Williams.

She was released from the facility around 7 p.m. on March 21, and was taken to a recovery facility, according to the report. Thomas was “sitting up in bed, speaking normally” the next day when she “suddenly” became unresponsive.

Thomas was rushed to a local hospital and died in the emergency room, the report said.

Mary Jane Thomas and Hank Williams Jr. in 2021.Jason Kempin/Getty

Mary Jane Thomas and Hank Williams Jr.

The Medical Examiner’s report said that Thomas' surgeon said her vitals were normal, and she was given Lovenox, an anticoagulant.

The autopsy report listed seven other findings, including mild brain swelling, mild coronary artery disease and fatty metamorphosis of the liver (which is a common finding in people who, like Thomas, had a history of alcoholism).

She and Williams, the 73-year-old son of late country legend Hank Williams, met in 1985 at one of his concerts and were married in 1990. They shared daughter Katherine, whodied in a car crash in 2020, and son Samuel, a musician.

Hank Williams Jr. and wife Mary Jane Thomas in 1989.Ron Galella/getty

Hank Williams Jr

Sam, 25, paid tribute to his late mother in a statement to PEOPLE shortly after her death.

source: people.com