Comedian Joan Rivers died from brain damage due to a lack of oxygen.

New York’s medical examiner’s office has ruled she died from low blood oxygen during a routine medical procedure to check out voice changes and reflux.

The 81-year old died September 4 after going into cardiac arrest August 28 at a doctor’s office.

The state health department is also investigating the circumstances of her death.

Her daughter and TV partner, Melissa Rivers, said they had no comment on the ruling, but issued this statement.

”We continue to be saddened by our tragic loss and grateful for the enormous outpouring of love and support from around the world.”