• Anne Heche's death was ruled an accident by the LA County Medical Examiner on Wednesday 
• The office also said the 53-year-old suffered a 'sternal fracture due to blunt trauma' in the horror smash on August 5
• Heche's life support machine was turned off on Sunday after she suffered horrific burns in the collision in her Mini Clubman 
• A spokesman for the Los Angeles Police said the department was continuing to investigate whether drug use contributed to the accident
• Blood tests showed that the actress had cocaine and fentanyl in her system 

Anne Heche's death has been officially ruled an accident after she died from her burns after plowing into a house at 90mph.

Los Angeles County Medical Examiner-Coroner on Wednesday ruled the actress passed away from inhalation of smoke and thermal injuries.

The office also said the 53-year-old suffered a 'sternal fracture due to blunt trauma' in the horror smash on August 5.

Sternal fractures are most commonly found in patients who chest struck the steering wheel in car accidents. 

Heche also suffered a 'severe anoxic brain injury' caused by a lack of oxygen, according to a statement released last week on behalf of her family and friends. 

A full autopsy report was still being completed, the coroner's office said. 

Heche's life support machine was turned off on Sunday after she suffered horrific burns in the collision in her Mini Clubman.

She was declared legally dead on August 12 after being in a coma for a week before being taken off life support two days later. She was kept on life support until her organs could be donated. 

A spokesman for the Los Angeles Police said the department was continuing to investigate whether drug use contributed to the accident.

Blood tests showed that the actress had cocaine and fentanyl in her system when the high-speed crash occurred on August 5, but officials confirmed that she had not been drinking alcohol, despite being pictured with a vodka bottle in her cupholder.

A new 911 call also revealed that neighbors were not initially aware that Heche was trapped in the car inside the property.

The caller told authorities a 'car just went through my neighbor’s house' and into the 'second room' and that no one was in the car, 911-call records, obtained by Fox News, said. 

When asked if the car was inside the house, the caller told the dispatcher that it was '10 feet' inside and moments later the car burst into flames with Heche inside. 

Seconds later, it was revealed that Heche was actually inside the car. The caller told dispatchers: 'Somebody is trapped in the car. It’s a big fire.' 

A dispatcher told the caller to 'try and get the driver out of the car if we can,' but advised them to stay safe.