bobbi kristina & bobby brown

*The release of Bobbi Kristina Brown‘s autopsy report on what would have been her 23rd birthday may have upset her father, Bobby Brown, so much that he cancelled his Charleston Jam Fest concert appearance in North Charleston, South Carolina on Friday (03-04-16).

Brown, 47, was scheduled to perform with Keith Sweat, Jagged Edge and 112, but according to signs on the doors of the arena, Brown opted out “due to illness,” Wonderwall reported.

“Charleston, I will see you soon but I had to sit out this time. I will be back soon and I can’t wait to hit the stage,” the singer tweeted on Saturday, one day after his scheduled appearance. “I can’t wait to hit the stage in New Jersey on March 26th and Tampa on April 2nd.”

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“I recently had surgery and the recovery time has taken longer than expected,” Brown continued. “My gastroenterologist has made the decision to keep me resting for another week.”

Meanwhile, as we reported on Friday, the autopsy of Bobbi Kristina was released to the public and according to the Fulton County Medical Examiner’s office, she died as a result of drowning and drug intoxication.

“The cause of Bobbi Kristina Brown’s death as determined by the Fulton County Medical Examiner is: Lobar pneumonia. Due to: Hypoxic ischemic encephalopathy, delayed effects. Due to: Immersion of face in water complicating mixed drug intoxication,” read the medical examiner’s statement

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The statement went on to detail that the drugs involved in her system were marijuana, alcohol, benzoylecgonine (a cocaine-related substance), benzodiazepines (medications used for sedation or to treat anxiety) and morphine.

The ME’s office also added, “It could not be determined from toxicology tests whether the morphine resulted from heroin use.”

In a statement to People, Brown said that the fact news outlets were trying to get the autopsy results released was “mind-blowing.” His attorney also said in a statement that the release of the results was “unsettling” and that the singer “has to be strong and mourn his loved ones in a fashion that is foreign to most people.”