Updated Wednesday, Aug. 15

Seven Washington relatives, including five children, killed Monday in a head-on crash in eastern Oregon were heading to Las Vegas for an end-of-summer trip, according to another family member.

Jessie Tate told The Oregonian/OregonLive during an interview Tuesday night that his sister, Erika Boquet, 29, of Tacoma left Lacey, Washington, early Monday morning with her children, Isabella Boquet, 11, Elisabeth Boquet, 8, and Tytis Boquet, 6, and another relative and that family member's two children. A 1999 Toyota 4Runner crashed into their 2016 Toyota 4Runner about 10 a.m. on Oregon 78 near milepost 30 southeast of Burns, Oregon State Police said.

Eight people died in the crash: The seven in the newer SUV and the lone person in the other SUV.

Tate declined to identify the other adult traveling with the Boquets, saying that person's immediate family wanted to wait until police notified the public of their identities. The Oregon State Police on Wednesday publicly identified the other three people in the newer SUV as Kyla Marie Brown, 28, of Olympia, Arianna Marie Brown, 10, and Xavier King Johnson, 2.

The driver of the other SUV was identified as Mark Robert Rundell, 48, of Prairie City.

The scene of the crash outside Burns on Monday, Aug. 13, 2018. (Oregon State Police via AP)

"It's a tragedy I wouldn't wish on anyone else," said Tate, 30, of Spanaway, Washington. He said the family has created a GoFundMe page to help with funeral costs.

Tate said his family is devastated by the unexpected deaths. He said he first learned of the crash from relatives who contacted him on social media. He then called his father, who told him who was involved.

Tate said his sister was devoted to volunteer work through a Tacoma-based nonprofit she created called Last Stop. The group, he said, provides resources to low-income families.

The group hosted an Easter egg hunt earlier this year, Tate said, and Boquet hoped to have a backpack drive before the school year began. She aimed to one day build a park in Tacoma.

"She was outgoing, personable, made friends everywhere she went, and her kids took after her," Tate said. "They all just cared about everyone around them."

Oregon State Police, who are investigating, said the driver traveling alone veered into opposing traffic on the two-lane highway while heading west and collided with the SUV carrying the family.

The collision is among the deadliest state crashes in recent years.

Five people were killed in a two-car crash near Salem in October. One driver involved was later charged with manslaughter, driving under the influence of intoxicants and other charges in the collision that killed a mother, her three children and her niece.

In 2012, nine passengers on a charter bus were killed and another 38 people on board injured when their bus slid on ice while traveling on an Interstate 84 mountain pass near Pendleton, crashed through a guardrail and plunged 200 feet into a ravine.

-- Everton Bailey Jr.

ebailey@oregonian.com

503-221-8343; @EvertonBailey

This report has been updated to include the identities of everyone involved in the crash.