DES MOINES — Catherine Veerhusen and her husband were driving northbound along the 80th Street SW bridge over U.S. Highway 30 in Cedar Rapids on Sunday when they spotted a herd of deer in front of them.

They had hoped the herd would somehow stay away from oncoming traffic while also not jumping over the bridge's west side.

But then the Atkins couple witnessed the lone buck sprint across to the opposite side of the bridge and vault over the bridge's sidewall to an estimated "20- to 30-foot" drop. The three does immediately followed — all leaping to their deaths.

Veerhusen was horrified.

"I've never seen anything like this," she told the Des Moines Register on Tuesday. "No words, no words."

When Ron Lane, a conservation officer with the Iowa Department of Natural Resources in Linn County, left the scene Tuesday afternoon, the three does remained but the buck was nowhere to be found.

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He believes the herd was panicked and not familiar with the area.

"The bridge there is brand new," Lane said. "I'm guessing the deer aren't used to that, with all of the construction going on."

Additionally, Iowa is in the midst of its second shotgun deer season, which Lane thinks could be another contributor the herd's disorientation, with hunters pushing them back.

"It sounds like with they were just trying to run across and didn't know where to go," Lane said.

Like Lane, Veerhusen also referred to the deer as "panicked." Riding in the passenger's seat of her vehicle, she explained what she saw at around 3:15 p.m. Sunday afternoon:

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"We see these deer cross the ramp in front of us and we're like, 'OK, don't go over the bridge,'" Veerhusen explained. "They went straight for the bridge. And we slowly

came up to them, keeping our distance, and we saw that this car was flying up (the road). We got in front of that car to slow them down. I don't think they saw these deer."

The Veerhusens slowed down Denny Benyshek, 50, of Fairfax. He told the Register he first saw the deer from about 200 yards out.

Warning: Some viewers might find this video disturbing.

"We were driving slow by them," Benyshek said as he and the Veerhusens got closer. "The buck was leading the whole time — then he just bolts straight east. The three doe followed him over."

He added that the event lasted just 15 seconds.

"It was pretty quick. I didn't even get to my phone in time. I was more busy watching them," Benyshek said, adding that he's a deer hunter. "I seen this rack and thought, 'That's a nice buck.'"

Benyshek and Veerhusen exchanged contact information, photos and video footage. Shortly after, Veerhusen posted her photos and video on her personal Facebook page.

The 2-second clip has accumulated 20 million views, and thousands of shares.

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She had to shut her account's notifications off due to the number of interactions the post generated.

"It has just taken off like crazy," Veerhusen said.

Benyshek, who's tagged in the post, agrees. He even went back out to the site around 5:45 p.m. Sunday and noticed the buck was missing.

"I told my wife today this is getting crazy. ... I had to put my phone down," he said.

Looking back, though, Veerhusen wishes she'd called the local sheriff's department. She and her husband stayed for "probably a good 10 to 15 minutes" afterward.

"I stood there — I was just in shock," Veerhusen said. " ... I've never seen them spooked like that."

Follow Aaron Young on Twitter: @AaYoung15