Investigators say the morning sun was a contributing factor in a 19-car pileup on Highway 417 Thursday morning that sent five people to hospital.

The crash happened near the Innes Road exit just before 7 a.m. and closed the highway for about three hours. The five people all suffered non-life-threatening injuries.

"At this point in the investigation, sun is being determined as a contributing factor," said OPP Acting Sgt. Tylor Copeland. "The sun was reported to be into eye level at that time."

Paramedics also assessed other people at the scene who weren't taken to hospital.

All lanes of the eastbound highway were closed for about three hours. They reopened just before 10 a.m.

One driver who was caught in traffic, Stephanie Boulerice, said the crash added about an hour to her commute. 

"People were turning around and driving the opposite direction that they were supposed to," she said. "So some people were coming face to face with oncoming cars and could have possible caused another accident, if anything."

Police are reminding people to reduce their speed, especially in the busy commuting hours.

- with files from Dave Charbonneau, CTV News Ottawa