A school bus rolled southeast of Calgary, sending seven people to hospital — just one of more than a hundred crashes in and around the city as snow and high winds created hazardous road conditions on Friday.

Nine people were aboard the bus when it partially rolled and landed in a ditch as it travelled eastbound in Vulcan County on Highway 542, just east of Highway 24. That's north of Vulcan and east of High River.

Eight elementary and junior high-aged students were on the bus along with one adult driver, according to a news release issued by Stuart Brideaux of Emergency Medical Services, Calgary zone.

Three patients — a 10-year-old male, a 12-year-old girl and a second male in his mid-teens — were taken to the Alberta Children's Hospital in stable condition with soft tissue injuries, paramedics said.

The four other passengers had only minor to no apparent injuries and were taken to Vulcan Hospital for assessment.

STARS air ambulance had to decline at least two calls on Friday because of poor weather conditions. (Airdrie RCMP)

One student was driven away by private vehicle, while the driver — a man in his 50s — wasn't injured.

RCMP are investigating the cause of the accident.

Snow and winds help cause collisions

Calgary police responded to 145 collisions on Friday between 6 p.m. and 9 p.m., including 15 in which people were hurt.

Outside the city, a fatal crash happened southwest of Calgary in MD Foothills on Highway 22 near Coalmine Road.

A sedan left the road, rolled and landed in a ditch, killing the 85-year-old male driver. The 87-year-old female passenger was taken to hospital in serious condition.

Another crash, in Rockyview north of the city, sent three people to hospital.

Two dump trucks hauling gravel collided head-on on Range Road 11 north of Highway 566.

Both drivers had to be extricated from their vehicles. One is in potential life-threatening condition. The other driver was in serious condition.

A passenger in one of the trucks, a man in his 40s, is also in serious condition.

Alberta EMS reported that high winds forced STARS air ambulance to decline two calls.

Caution urged over long weekend

Anyone planning to head out of the city for the long weekend should check road reports at 511.ab.

Last year, four people were killed and 68 injured in collisions over the Thanksgiving weekend, said RCMP Sgt. Jack Poitras.

"Our increased presence on Alberta roadways is not about writing tickets but reducing those statistics. More patrols on roadways are intended to deter dangerous driving behaviour and make our roads safer for everyone."

Poitras points out that, with harvest still underway in parts of the province, motorists can expect to see farm equipment on rural roads. He also advises drivers to keep an eye out for cyclists, motorcycles, and pedestrians.

Airdrie police also issued a list of reminders for safe driving in winter-like conditions.

Reduce your speed and wear your seatbelt.

Turn on your vehicle's headlights/taillights to increase visibility.

Increase the distance between your vehicle and others on the road to allow more time for stopping.

Ensure you have a full tank of gas before venturing out as there could be delays due to accidents or stalled vehicles.

Obey directions from police and emergency personnel you may encounter on the road.

Pack warm clothes, such as gloves/mittens, hats, tuques and blankets in the car in case you have a mechanical breakdown or have to wait in a traffic backup.