SPOKANE COUNTY, Wash. -

Family and friends are mourning the loss of six people who died on Thursday in four separate accidents on Eastern Washington highways.

"I've never seen anything like this before," Washington State Patrol Sergeant Chuck Arnold said.

Sergeant Arnold says this is a first in his 18-year-career.

"They've been spread out to all different areas within our district and that's unusual to see four in one day," Sergeant Arnold said.

The first one occurred just a little before 5 a.m. Three people from Spokane were killed when their vehicle slammed into a bridge pillar at the Tokio exit on Interstate 90 near Ritzville. Investigators believe that the driver, 20-year-old Gabriel Johnson, fell asleep at the wheel and swerved into the highway structure. The crash killed him and his two passengers, 21-year-old Mary Werts and 19-year-old Trevor Hallman-Person.

Hours later, 34-year-old Jay Pratt was killed on Highway 395 near Kettle Falls when his car collided with another in the southbound lane. He was transferred to the hospital, but later died. The driver in the other car sustained minor injuries.

Then at noon, 96-year-old Renard Faraca of Spokane was killed when he pulled onto Highway 195 near Cheney-Spokane Road and hit a car going southbound.

The fourth fatality occurred in Whitman County just before 4 p.m. The Washington State Patrol said 84-year-old Oren Pillers of Colfax was driving northbound on State Route 127 when he over corrected and lost control. He stuck a fixed object and died on scene.

"Based on our preliminary investigation, there's nothing that links any of them together or common factor that attributes to any of the four,” Sergeant Arnold said.

Warmer weather will mean busier roads. With more drivers on the streets, that means an increased chance for collisions.

"More distractions, more traffic volume, more motorcycles, more people wanting to get out and about to different destinations," Sergeant Arnold said.

He adds the primary reason for collisions is speed. He asks everyone to slow down and pay attention, so we can all have a safe summer.