A serious three-vehicle collision sent six people, including five Chinese nationals, to hospital with one in very serious condition.

On Saturday at about 11 a.m., police and emergency services were called to the scene on Trafalgar Road, south of Derry Road in Milton.

Police said a northbound Toyota driven by a Mississauga man lost control and veered into the southbound lanes, smashing into a Kia with five male occupants.

After the initial collision, the both cars were hit be a third vehicle, a Pontiac, driven by an Orangeville woman, police said.

The Toyota driver was trapped in his car and had to be extricated. Investigators said they don't know why the driver of the Toyota lost control.

He was transported by ambulance to Credit Valley Hospital with serious but not life-threatening injuries.

The driver of the Kia, also a Mississauga man, sustained injuries and was taken to Milton District Hospital with 3 of his passengers.

A fourth passenger was rushed to Hamilton General Hospital where he remains in very serious condition. He is described as a 25-year-old resident of Tianjin, China.

The four passengers in the KIA are Chinese nationals in Canada on contract work for a Brampton manufacturing company. Company officials are assisting police with notifying next of kin in China.

Trafalgar Road was closed for several hours while police completed their investigation at the scene. The lanes are now open, police said.

The driver of the Pontiac said weather conditions were clear at the time.

"I am shaken up and a little sore, but I am ok," said Nancy Monaghan, adding that she was going to a baby shower in Burlington when the incident took place.

The woman said she, along with a number of bystanders, helped other crash victims to safety.

"We got them out because the car was smoking," she added.

Witnesses are asked to contact detective constable Greg Cormier at (905) 825-4747 ext. 5066.