The stool collapsed and Permar's arm got stuck at around 2am on Sunday, and an autopsy on Monday revealed Permar's left arm and wrist were broken.
She was unable to free herself, and the 56-year-old was found dead at the bin around 8.30am.
"She was fishing bags out and the ladder she was standing on gave way and she couldn't get her hand loose," Hollenbush said.
Bags filled with clothes and shoes littered the ground and her Hummer was parked nearby with the engine still running, he said.
The police had received reports in November of a woman with a black Hummer who was removing bags from the bin, he added.
Permar leaves behind her husband, three sons, one daughter and four grandchildren.
Her daughter Angela Minnig wrote a tribute on Facebook that read: "On Sunday morning my Mother passed away. It was very sudden and our family will learn to cope with the loss of such an amazing Wife, Mother, Sister, and Friend.
"She was such a fun loving person and we know it would mean the world to her to say "See you Again."
She was described as an active and energetic woman who adored cats and enjoyed cooking, baking and gardening, according to her obituary.