It was there police say she quickly realized she was going into labor and soon give birth to a premature baby boy.
Though he arrived at least a month early, the baby was otherwise healthy, according to County Coroner Zachary Lysek.
The 26-year-old would later confess to investigators that she suffocated the child with a garbage bag, and left his body inside a toilet tank.
Covered in blood, Hein eventually returned to her party after a 40-minute absence, but refused to tell the men what happened.
She reportedly continued watching the WWE SummerSlam for another hour before leaving the bar.
A friend of Hein's said she refused medical assistance, claiming she didn't have insurance. None of the men had any idea Hein was pregnant.
The identity of the father remains unknown.
Hein was subsequently arrested and charged with the intentional killing of a child under the age of 12.
If convicted, she faces a possible death sentence.