FLORENCE, S.C. -- A Canadian soldier, his wife and their infant son have been killed in a fiery weekend crash on an interstate highway in South Carolina.

U.S. authorities say Jeremiah Cross, 34, Crystal Cross, 32, and seven-month-old Grayson Cross were among the victims in the crash on Interstate 95, which also took the lives of two Pennsylvania residents.

Capt. Jeremy Mathews at Garrison Petawawa northwest of Ottawa says Cross was a private with 2 Service Battalion in Petawawa but had no other immediate details.

Media outlets in South Carolina say the crash happened Saturday night on the northbound lanes of the heavily travelled interstate in Florence County, which is about 100 kilometres northwest of Myrtle Beach.

The collision, which is still under investigation, involved five vehicles including two tractor trailers.

Two of the cars in the crash caught fire. Traffic on the northbound lanes of the interstate was blocked for about 12 hours.

The U.S. victims have been identified as Jacqueline McCann, 51, and Barry Himes, 52, both of Johnstown, Pa.

With files from The Associated Press.