RCMP in Alberta say they have charged the driver of a semi tractor trailer involved in a fatal crash last summer.

The crash happened Aug. 7 near Oyen, Alta., 300 kilometres east of Calgary.

Bob Chaylt Jeffreys, 41, was driving with his wife, Carla Chambers Jeffreys, 36, and their three children when they stopped at a construction zone behind a semi-trailer on Highway 9.

The family's minivan was struck from behind by another semi-trailer, which propelled them into the vehicle in front of them, say RCMP.

Zachary, 10, was killed on impact.

Lillian, 8, Gabriel, 7, and Carla Chambers Jeffreys were all seriously injured and have needed extensive medical care and rehabilitation.

Neither of the drivers of the semi-trailers was injured.

Lowell Nathan Dyck, 37, now faces one count of dangerous operation of a motor vehicle causing death and criminal negligence causing death, RCMP said in a release on Wednesday.

He has also been charged with four counts each of criminal negligence causing bodily harm and dangerous operation of a motor vehicle causing bodily harm.

Police say Dyck is scheduled to appear in court in Hanna, Alta., on April 22.

The family was moving to St. Catharines, Ont., from Vancouver when the crash happened.

A GoFundMe page set up to help the family pay its expenses has raised more than $100,000 so far.