Traffic was clogged on state Highway 503 after seven cars crashed, one after the other, in a chain-reaction, rear-end collision during Wednesday evening’s rush-hour commute.At 5:19 p.m., Jason Dearmin, 19, of Yacolt was driving a 1989 Jeep Cherokee north on Highway 503 at Northeast 95th Street when he collided with a 1991 Ford Escort driven by a Haley Ross Stevens, 16, of Oregon City, Ore., said Sgt. Gabe Olson of the Washington State Patrol. The teen’s car was pushed into the back of a 1998 Subaru Forester driven by Krysta Mason, 29, of Battle Ground.A second three-car collision smashed into the first collision.Miguel Sandoval, 60, of Battle Ground was driving a 1998 Chevrolet S-10 pickup and hit a 1995 Plymouth Neon driven by Courtney Millard, 19, of Battle Ground, the WSP’s Olson said. Millard’s Neon was pushed into a 1992 Toyota Camry, driven by James Lindberg, 52, of Battle Ground. His Camry was pushed into the back of Dearmin’s Jeep Cherokee.Lastly, Kelly McEllrath, 60, of Battle Ground, who was driving a 1991 Honda Accord, rear-ended Sandoval’s pickup, Olson said.No one was seriously injured in the pileup, Olson said. Sandoval and Ross Stevens were being treated at PeaceHealth Southwest Medical Center late Wednesday night. Three of the vehicles were towed from the scene.Three state troopers responded, along with the Vancouver Fire Department and two AMR ambulances.Another non-injury crash occurred at Northeast 76th Street about 30 minutes later.Olson advises drivers to be more attentive and increase following distance when the roads are slick.