Two Ontario parents are demanding answers from their son's school after their six-year-old child missed the bus and walked home alone, crossing a busy intersection during rush hour.

Brantford residents Andrew Heubach and Dawn Russell say their son, Lucas, was not on board his school bus with his sister last week. Heubach, who picks up his children at the bus stop, panicked and called the school, Ecole Fairview.

"I called the school, and there was nobody there to answer the phone; I just got the answering machine," Heubach told CTV Kitchener over the weekend. "So I left a message saying, 'I've been everywhere I possibly can – at this point in time, my son is missing."

According to the parents, the school did not learn about the incident until the following day. But Lucas eventually made it home.

Approximately 30 minutes after he was supposed to be dropped off, the Grade 1 student was spotted by his mother walking up the street.

"He said he missed his bus. When it hit me that he walked home from the school, I felt sick because I know how busy that road is," Russell said.

Although it is only a short distance between Lucas' school and his home, his parents says the 15-minute walk includes crossing a busy intersection. Heubach says his son did not use the crosswalk at that intersection because he couldn't find it.

"He said … 'the cars just let me go,' and my heart just went into my throat," he said. "That's when I started losing it."

Lucas' parents say their son saw his school bus leaving and tried to chase it down before deciding to walk home alone. They are now asking questions about the school's busing policy and why no one noticed Lucas wasn't on his bus.

"He ran through the school ground where there should have been at least two … staff members out there who didn’t notice anything had happened," Russell said.

The Grand Erie District School Board is now investigating the incident.

"I think what we have to do is to make sure we’re looking at communication and that would be communication with everyone that's involved," said Scott Sincerbox, the superintendent of the board.

"And then of course we have to make sure we're working with the administration of the school, the teachers in the classrooms, the children that are there, and of course, the parents."

Meanwhile, both Heubach and Russell say a new policy that involves checking off the names of students that are supposed to be on a bus should be introduced across the board.

With a report from CTV Kitchener's Ginella Massa