NEW YORK (AP) – A woman who died unnoticed on a hospital floor in an upsetting scene recorded by security cameras was killed by blood clots caused by a long period of physical inactivity, according to the city’s medical examiner.

Esmin Green, 49, had been sitting in a waiting room at the city-owned Kings County Hospital Center for nearly 24 hours when she collapsed from her chair and slowly died on June 19.

After an autopsy and weeks of tests, the medical examiner’s office concluded Friday that Green was killed by pulmonary thromboemboli, blood clots that form in the legs and travel through the bloodstream to the lungs.

A recording of her death prompted national outrage when it became public last week.

Two security guards and a member of the hospital’s medical staff can be seen on the video, stopping to look at Green briefly before walking away. She stopped moving about 30 minutes after falling and was dead when a nurse finally examined her another 30 minutes after that.

An attorney for Green’s family, Sanford Rubenstein, said “The length of time that she spent in the emergency room … very well may have contributed to her death.”

HHC officials have previously expressed outrage at the way Green was treated. Six employees lost their jobs over the incident, even before it became public.

The agency also immediately reported the death to the state and voluntarily turned over the security records to lawyers already suing the city over alleged patient neglect at the hospital.