A 75-year-old Blaine woman and an 87-year-old Camano Island man were killed Tuesday when the vehicle they were traveling in was hit by a semi-trailer truck on I-5 near Snohomish.

Washington State Patrol troopers said Barbara Humberson was a passenger in a 2001 Honda Accord that was stopped or traveling slowly on southbound I-5 when it was struck from behind by a 2005 Freightliner. The accident occurred on Tuesday at about 3:30 a.m., just north of 172nd Street Northeast. Troopers said the driver of the semi braked hard but there wasn’t enough distance to stop in time.

Humberson was pronounced dead at the scene.

The driver of the Accord, Robert Gwaltney, 87, of Camano Island, was transported by air to Harborview Medical Center where he later died.

The driver of the semi was uninjured in the collision.

Troopers said there was no indication that alcohol or drugs were a factor in the collision for either driver and that they are investigating why Gwaltney was traveling at such a slow rate of speed.