As state trooper Kristie Sue Hathaway sat in her squad car during a crash investigation in Eagan Thursday morning, she glanced in her rearview mirror and saw an F-150 pickup rapidly approaching.

She hoped the driver would see the flashing lights and veer around her, but no. Wham, the pickup plowed into the back of her cruiser at an estimated speed of 60 miles per hour.

Neither Hathaway nor the person in the back seat was seriously injured, but Hathaway became one of four troopers hit Thursday morning to Friday morning while responding to crashes.

It was likely a record for the number of troopers hit in a 24-hour period, said Lt. Tiffani Nielson of the State Patrol.

In all cases, driver conduct — not the treacherous roads caused by a snowstorm — was the biggest factor, Nielson said, citing excessive speeds and following too close as ­particular problems.

"Bad habits are not easy to correct on poor weather days. That's why we are seeing an increased number of incidents," Nielson said. "And troopers getting hit."

In total, the patrol responded to 855 incidents between 8 a.m. Thursday and 10 a.m. Friday. That included 610 spinouts and 110 crashes with injuries. Besides Hathaway in Eagan, troopers' squads were hit in Brooklyn Center, Virginia and Marshall.

None of the troopers ­suffered serious injury.

Hathaway, a four-year member of the patrol, had stopped in the left lane of eastbound I-494 near Pilot Knob Road at 1:47 a.m. Thursday where a car had spun out. She turned on her lights and pulled her squad behind the tow truck that was loading up the damaged car. With the car's driver in the back seat, Hathaway looked in the rearview mirror and saw headlights getting brighter as the truck got closer. She braced for impact.

"I was hoping he'd swerve or decrease speed to make the impact less," Hathaway said during a media briefing Friday with her crumpled squad car in the background. "The squad car tells the story. I didn't grasp the impact until seeing it in the daylight.

"When I took this job, I realized it's not if you are going to get hit but when. Luckily I was not outside the squad. Had I been outside I would have been walking in front of the squad. Things could have been much worse."

Both Hathaway and the driver of the disabled car were treated at a hospital and released.

The pickup driver was arrested on suspicion of drunken driving.