OTTAWA -- Three people are in critical condition after a crash in Kanata late Friday morning.

Emergency crews were called to Terry Fox Drive, just west of Old Second Line Road at around 11:40 a.m. Friday on reports of a two-car collision.

"It is one of the worst accidents I've seen as a head-on," said Ottawa Police Sgt. Mark Gatien. "The cars are melded into what looks like one vehicle. If they were one colour, it would look like one car."

Ottawa police say an SUV travelling north on Terry Fox Drive crossed the centre line. What caused the driver to cross into opposing lanes is unknown, but Gatien said there was no time for the other driver to react.

"The car crossed over at the last second," Gatien said, "there was no time to react on the other portion."

Police said a woman in her 60s was in the SUV, while a man and woman in their 60s were in the other vehicle.

Three people were trapped in the two cars. Firefighters were able to extricate the trapped passengers by 12:00 p.m.

In a press release, Ottawa Paramedics said three people—a 66-year-old man and two women in their 60s—were taken to the trauma centre in critical condition with multiple injuries.

"All three were determined to be in critical condition," said Ottawa Paramedic Service Public Information Officer Emily Fullarton. "Two female patients had serious multi-system trauma, meaning they could have non-visible injuries, based on their vital signs."

Fullarton said the patients did not have any injuries that were deemed to be immediately life-threatening, allowing paramedics to quickly transport them to hospital.

It is still early in the police investigation, but weather and sun glare have been ruled out as potential causes. Police have not yet ruled out the possibilty that a medical emergency may have contributed to the crash.