ARAPAHOE COUNTY, Colo. — No charges will be filed in the death of Colorado State Patrol master trooper William Moden, it was announced Thursday.

Investigators are calling Moden’s death an accident.

He was killed when a driver hit him on Interstate 70 in eastern Arapahoe County while responding to a rollover crash on June 14.

The Colorado State Patrol and 18th Judicial District Attorney George Brauchler said there was no misconduct by the driver who hit Moden.

“The right thing to do is sometimes not easy or obvious” Brauchler said.

The accident happened about 9:45 p.m. on Interstate 70 near Deer Trail.

Moden was outside his vehicle responding to the rollover crash involving a young mom and her baby when the driver crashed into him.

Investigators say Moden, whose vehicle was on the side of the highway, was doing reconstruction work when he was hit in the westbound lane by the driver who did not see him in the dark.

The driver stayed at the scene, cooperated with the investigation and was later determined to not have drugs or alcohol in his system.

Investigators add he wasn’t driving careless, just that he couldn’t react fast enough before hitting Moden.

The mother in the rollover crash, 22-year-old Madison Fitchett-Howard, has been charged with reckless endangerment, reckless driving and child abuse — all misdemeanors.

She and her 18-month-old were thrown from the vehicle, which troopers say was going 100 mph when she crashed.

It is believed Fitchett-Howard was under the influence of alcohol, but toxicology tests are still pending that could lead to more charges.

The baby, who was not properly restrained, suffered minor injuries. Fitchett-Howard suffered serious injuries.

Fitchett-Howard will be arraigned in Arapahoe County court on Oct. 10.

Moden was a 12-year veteran of the Colorado State Patrol. He is the fifth trooper killed in the line of duty on Colorado roads since 2015.