Jeremy Renner was trying to save nephew from injury when he was crushed by snowplow, sheriff's report says

The parking break was not engaged and would have stopped the snowcat vehicle, which runs on a track, as it started sliding sideways after the 52-year-old "Avengers" star used it to pull his nephew's truck out of snow, according to the redacted Washoe County Sheriff's Office report, filed Friday.

Keep scrolling for photos from Renner's career

"The Pistenbully snow groomer began sliding causing Renner to exit the vehicle without setting the emergency brake," reads the conclusion of the report, which CNN obtained Tuesday through a public records request.

"Although the Pistenbully had some mechanical issues, it is believed based on our mechanical inspection that the parking brake would keep the Pistenbully from moving forward. When Renner attempted to stop or divert the Pistenbully to avoid injury to (his nephew), he was pulled under the vehicle by the track and run over."

The brake indicator light inside the snowcat's cab was not functioning, and "mechanical issues may have been a factor in this accident," the report also notes.

The nephew was able to help Renner until help arrived, the report states. Renner was airlifted to the hospital, where he stayed for more than two weeks, undergoing at least two surgeries and being treated in the intensive care unit.

Impairment was not believed to be a factor in the incident, the report also concludes. CNN has reached out to Renner's representatives for comment.

Moving track pulled actor under, report states

The incident began on New Year's Day, when Renner towed his nephew's truck off the actor's driveway after it had been stuck in snow, he told investigators on January 5 while hospitalized, according to the incident report.

After towing the truck into the street, the snowplow began "sliding sideways," then "it began to roll down the hill," Renner said. At that point, Renner jumped out of the snowcat, he told investigators.

"Once he was off the Pistenbully, he realized it was heading directly toward (his nephew)," the report reads. "He feared the Pistenbully was going to hit (his nephew), so he decided to attempt to stop or divert the Pistenbully."

To enter the snowplow's cab, Renner had to climb onto its moving track and was "immediately pulled under the left side track," the report notes.

Renner was "completely crushed under a large snowcat (vehicle)" and had "extreme (difficulty) breathing," with "the right side of his chest ... collapsed -- upper torso is crushed," a 911 call log obtained by CNN said.

"The Pistenbully rolled over him and continued down the road," the report says. "He laid on the ground and focused on his breathing while (his nephew and others) rendered aid to him until medical personnel arrived on scene."

Renner, who plays superhero archer Hawkeye in the Marvel movie and TV "Universe," broke more than 30 bones in the incident, he's said.

He posted a photo on Instagram last week with a caption that read: 

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