The Wyoming Highway Patrol says driver fatigue may be to blame for a crash that left a Washington mother and son dead.

The crash happened around 3:40 p.m. on Sept. 23 near mile marker 294 on Interstate 80, about 16 miles west of Laramie.

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According to a fatality crash summary, a Freightliner box truck was illegally parked in the eastbound emergency lane when a Chevrolet HHR left its lane to the right and collided with the parked Freightliner.

The collision left two passengers, 65-year-old Michael Post, who was not wearing his seat belt, and 84-year-old Shirley Alderman, who was buckled up, dead.

Another person was also reportedly injured in the crash and one escaped injury.

Calls to the Highway Patrol seeking more information were not immediately returned.

According to Shirley's obituary, Michael was one of her seven children.

Of the 108 people who have died on Wyoming's highways so far this year, 26, or 24.07%, have died in crashes on I-80.

LOOK: Most dangerous states to drive in

Stacker used the Federal Highway Administration's 2020 Highway Statistics report to rank states by the fatalities per billion miles traveled. 

Gallery Credit: Katherine Gallagher

2022's Deadliest Wyoming County by Traffic Deaths

While car crashes can occur anywhere, some roads in Wyoming are more dangerous than others.

According to Wyoming Highway Patrol data, there were 117 fatal crashes in the Cowboy State in 2022 resulting in 133 deaths.

Of those fatal crashes, the majority (13.68%) occurred in Laramie County -- two in January, one in February, one in March, two in April, one in June, two in July, three in August, two in September, one in November, and one in December.

Sweetwater County saw the second most fatal crashes last year, 12, while Fremont and Lincoln counties each saw 10.

Albany and Park counties each recorded eight, and Campbell, Converse, and Natrona counties each tallied seven.

The deadliest 2022 crash in Laramie County took place on June 17 when two semis collided on Interstate 80 east of Cheyenne and immediately became engulfed in flames killing both drivers and a passenger.

Laramie County also saw two fatal crashes involving motorcyclists, two fatal crashes involving juveniles, and a fatal crash involving a pedestrian last year.

Below is the Wyoming Highway Patrol narrative of every fatal crash that occurred in Laramie County in 2022.

Gallery Credit: Joy Greenwald

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