Four-year-old Ava Buckareff is hardly aware, but her mother Julie is holding her little girl a little tighter after a terrifying experience on the subway.

"I hugged her. I held her. I cried for 45 minutes. Just the possibility of what could have happened," said Julie, remembering the fear and the terror that ensued when her daughter tried to step onto a subway train last Wednesday.

Here's what happened: 

Ava was on her way home with her aunt and her older brother, Ethan.

When she stepped towards the open door, she fell between the subway train and the platform.

"She stepped in the gap and slid full through. You could only see one arm sticking up holding onto the platform. And her head," said Ethan. 

"There's a moment of sheer terror, right," said Esther Buckareff, the little girl's aunt. 

People screamed at the driver not to pull away. 

"There was someone that was banging very hard on the window of the driver; And he didn't hear anything," said Esther.

She grabbed her niece by the arm and hoisted her onto the train just seconds before the doors closed.

"It never crossed my mind the space was that big," said the aunt. 

The size of the gap really depends where on the platform you're standing and the particular train.

Julia Buckareff would like to see something done so no one else falls through the gap.

"We don't want anyone else to get hurt. We want to make sure the TTC fixes the situation."

The TTC says it is investigating why the driver didn't hear the commotion, but says it has no plans to change station platforms. 

It will, however, install another warning sign at the St. Clair station.