ELLENSBURG- A fatal accident caused a major traffic backup on an already holiday-congested Interstate 90 Monday afternoon.

#UPDATE I-90 MP 110 (Ellensburg) Collision. MEDIA MUST STAGE BEHIND LAST PATROL CAR WITHIN DOT CONES. Tragically 1 adult & 1 child are deceased. 1 adult & 2 children airlifted to Seattle. Total involved 3 adults & 6 children. PLEASE BE PATIENT AS @wastatepatrol INVESTIGATES. pic.twitter.com/8y4GuncN0C — Trooper Brian Moore (@wspd6pio) September 4, 2018

The one-vehicle crash left 2 dead and 6 injured, all from the same family. The State Patrol report says it happened when a 40-foot motorhome, driven by a 62-year old Snohomish man suffered a blown tire, lost control of the RV, left the roadway and crashed down an embankment into a creek off the highway about a mile South of Ellensburg.

Killed in the accident was a 61-year old woman and her 6-year old granddaughter. The five other siblings injured in the crash ranged in age from 3-years-old to 15-years-old and were airlifted to area hospitals including Harborview Medical Center and Virginia Mason Hospital in Seattle as well as Kittitas Valley Healthcare in Ellensburg and Central Washington Hospital in Wenatchee.

The children’s 41-year old mother was also seriously injured in the crash and taken to Harborview Medical Center.