A Vancouver mother says she is angry and frustrated with TransLink after the door of a bus closed on the head of her son, who has autism.

Adrienne Sweat and her five-year-old son Liam live near Grandview Park on Commercial Drive. The two were headed home Thursday when they decided to take a bus instead of walking 12 blocks. 

"I was getting change out of my wallet, let go of his hand and he started to climb up on to the bus," she told CBC News in an interview.

Adrienne, Liam Sweat

Adrienne Sweat says the bus driver's actions should be investigated because it's important drivers are "watching out" and "paying attention." (CBC)

Sweat says the doors closed on Liam's head and the Coast Mountain bus driver, who she claims wasn't paying attention, didn't react quickly enough.

"He finally opened the door, and I managed to get him out and then he closed the doors and drove away," she said. "He didn't say anything — didn't stop to see if we were OK."

Sweat says her son was crying, but was not seriously injured. She's since filed a complaint with TransLink.

"It's so important that they watch out and pay attention," she said. "And it would be nice to know what was going on. What if there's a higher safety concern with that bus driver and maybe his job needs to be looked at?"

Adrienne, Liam Sweat

Coast Mountain Bus Company says it will look at video camera from the bus. It says it takes these kinds of complaints seriously. (CBC)

TransLink received more than 31,000 complaints last year — half of them were about Coast Mountain staff. The company says it will be reviewing video from the bus.

"We take situations like this very seriously," said Coast Mountain vice president Michael Madill. 

"Safety is our top priority and really all of our instructions we do with transit operators' centres around safe operating procedures and customer service."

Madill says the investigation will take a few weeks.

With files from the CBC's Bal Brach