A Toronto mother says her disabled daughter is still traumatized more than a week after being forgotten on board a school bus and left in the cold for six hours.

Laura Mastache says her daughter Wendy, who has both autism and epilepsy, has been noticeably more reserved and withdrawn since the incident on Jan. 23.

Mastache says the driver picked Wendy up as scheduled that morning, and was supposed to drop her off at the back entrance of a Toronto high school where the 19-year-old's special education program is held.

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But the driver only dropped the students off at the front door, forgetting to take Wendy to her destination and leaving her on the bus, without heat, until it was time to take students home at the end of the day.

The incident prompted the Toronto District School Board to change one of its attendance notification policies and resulted in the bus driver losing her job.

Mastache says such actions can't ever answer the questions that linger as she and her daughter struggle to make sense of what happened.