Two Marysville residents were injured in the 27-car pileup in Mount Vernon Saturday, July 18.

James M. Sweeney, 69, was northbound driving a 2006 Mazda with Julie M. Sweeney, 58, when a semi-truck heading south suddenly veered left off Interstate 5. It crashed through the cable barriers and on to oncoming traffic, hitting the car with the Sweeneys in it, along with four others.

The Sweeneys were transported to Skagit Valley Hospital.

Joseph F. Steiner, 60, of Everson, who was driving the semi, may have had a medical emergency, the Washington State Patrol reported. He was transported to Harborview Medical Center in Seattle. He was driving a Mack dump truck towing a trailer.

Four people in three other vehicles also were injured and taken to various hospitals. A total of 21 cars and two trucks were involved in the 8:26 a.m. accident. The highway was blocked for hours, causing major detours and delays all day. No one in the other vehicles reported injuries.