Two members of a Canadian family were killed on July 4 in a tragic crash in Northeastern Pennsylvania.

The accident occurred on northbound Interstate 81 in the Lackawanna County community of Scott Township. The family car, which held two adults, their son and their daughter, was traveling near the Fleetville exit around 4 p.m., on the holiday when a tractor-trailer rear-ended the vehicle.

Killed were the 45-year-old father and his 10-year-old son, according to the Lackawanna County coroner’s office. The mother and daughter were taken to the hospital, and their condition wasn’t immediately known.

Investigators said the car carrying the family was stopped in traffic because of an accident that occurred earlier. The truck driver didn’t see the stopped cars and rammed into the family car, authorities said.

The truck driver also was transported to the hospital. His condition also was not available.

The crash and the ensuing investigation by state police led to the closure of Interstate 81’s northbound lane for five hours; traffic also was slow on the southbound lanes. Clearing the accident site required crews using heavy equipment.

State police did not immediately announce any charges against the driver.

We don’t know if the family was heading home from a long-awaited vacation or just what brought them south to the United States. But we do know one thing: At all times, drivers are responsible for staying alert, keeping their eyes on the road and looking ahead for any possible slowdowns.

It’s too soon to know whether the truck driver was distracted or was driving too fast to stop. Whatever the case, tragedy ensued, and the woman and her daughter will need support both emotionally and physically moving forward. A Pennsylvania attorney with experience in personal injury cases could answer questions the woman has as she processes the loss of her partner and their son.