Aimee Bridge knew something was wrong the moment she saw her brother Preston's mates in a crowd of police, paramedics and onlookers gathered around an unfolding tragedy outside a Scarborough resort.
The 20-year-old and her father Rodney were driving home after breakfast when they came upon the scene outside the Sunmoon Resort shortly after 10am on Saturday.
"My dad went over there and when I saw his face on the way back to car, I knew that something had happened and that's when we drove to pick up Mum and came straight (to Sir Charles Gairdner Hospital)," Miss Bridge said.
Within hours, the extent of the tragedy was apparent. Preston Bridge had suffered a catastrophic head injury after falling from a balcony at the resort that would result in the 16-year-old's death on Monday.
"All I know is he fell from a building and he cracked his head," his mother Vicki Bridge said.
"The truth to me was this injury was caused from a fall, for whatever reason, for whatever he was trying to do or achieve, and unfortunately he hit his head very badly."
The popular teenager and accomplished athlete had been at the Churchlands Senior High School Year 12 ball at the Perth Convention and Exhibition Centre on Friday.
Ms Bridge dropped her son off at a pre-ball party, while Mr Bridge picked him up once the ball finished and took him to an after-ball party at a friend's house.
Preston planned to stay at the friend's place but police believe Preston went to the Sunmoon with two girls and five boys about 3am on Saturday. By 10am, he was the only one of the group still in the room.
He fell as one of his friends ran up the stairs to urge him to hurry up.
It is understood the room had been hired by a parent of one of the group, but Ms Bridge said she did not know whether an adult was present to supervise or if her son stayed at the resort in those early hours of Saturday. "I don't believe he was staying there," she said.
By Sunday, the family were bracing for the worst.
More than 150 relatives and friends from football circles and the school were ushered through the intensive care unit to say their goodbyes.
Joan Bridge-Ward described her final moment with her "dream" grandson. "I had to give him a kiss on the forehead. I don't know why, but that's what I wanted to do," she said. "It was my goodbye."
Preston's family are arranging for his organs to be donated. "For us that gives us the hope that we can save somebody else," Ms Bridge said. "This is what he would have wanted and we all agreed.
"He was a definite leader and mentor to many age groups. He continually gave people advice and was a real healer on this world.
"I don't know what we can do as parents, just check what they're doing and keep an eye on them is all I can say. I thought we did a good job of that with Preston, but no one's invincible."
WA Secondary School Executives Association president Rob Nairn said principals could not assume duty of care for students once they were no longer in their care.
"It is a tragic loss under any circumstance but schools don't have any control over what happens outside the ball," he said.
Churchlands principal Neil Hunt said schools could recommend that parents look at safety aspects of after-ball parties and know where their children are going to be.