MOUNT VERNON -- Northbound lanes of Interstate 5 were closed for several hours near Anderson Rd. in Mount Vernon, following a multi-vehicle collision Saturday morning.
The crashes happened around 8:30 a.m. just south of an ongoing criminal investigation, which had shut down the roadway earlier in the morning.
Washington State Patrol troopers said a semi-truck hauling gravel was traveling south, when the driver crossed the median and smashed into stopped traffic in the northbound lanes.
WSP confirms a total of 28 vehicles were involved.
The semi-truck driver and the first person hit were taken to Harborview with critical injuries. Four others were taken to hospitals in Skagit County, with injuries ranging from broken bones to general pain.
Troopers are still working to determine what caused the semi-truck driver to lose control, but they believe it may be related to a medical condition.
He has not been identified, but WSP says the driver is a 60-year-old man from Everson.
The interstate reopened around 6 p.m..