Distracted driving among teenage boys trying to catch the eye of a girl who passed by on an interstate near Hudson, Wis., is being blamed for the schoolmates' vehicle crashing and killing three of them last week, authorities said Wednesday.

With Zachary D. Zajec, 17, looking down in the center console for a piece of paper, his SUV slammed into the back of a semitrailer truck that was stopped in heavy traffic on eastbound Interstate 94.

Also killed in the July 30 crash were Joshua J. Goodrich, 17, and Jordan M. Johnson, 16. Thomas Wanless, 17, was slightly hurt. All four recently completed their junior year at New Richmond (Wis.) High School.

The teens were returning to New Richmond from shopping in Woodbury, when the boys were traveling in the left-hand lane and "saw a girl driving in the right-hand lane," said State Patrol Sgt. Brian Erickson, citing an account from Wanless. "They wanted to get her attention ... 'Hey, see us.' "

They were trying to "put their phone number on a piece of paper and show it out the window to the girl" whom they did not know, the sergeant added.

In an attempt to find paper, Johnson unfastened his seat belt in the back seat while Zajec searched the center console, Erickson said.

Having completed "most aspects of the crash investigation," Erickson said, the evidence and accounts from witnesses and survivors point to "distracted driving [as] a significant contributing factor" in the SUV striking the rear of the flatbed semi 6 miles east of Hudson in a construction zone.

While Zajec's father acknowledged that boys can be distracted by the opposite sex while driving, he focused most of his criticism on the state Department of Transportation for what he said was a faulty warning sign ahead of the construction zone.

"As a child, did I do the same thing? Which man didn't," said Doug Taylor of the boys' attention on the girl. "But more important, I want to know why the warning sign wasn't on."

Taylor said a large sign telling drivers of construction ahead was not illuminated at the time of the crash and was still not working when he drove that same stretch of interstate on Monday, the day his son died.

"Nobody has mentioned anything about this faulty sign," Taylor said. "In my heart, yes, it would've made a difference."

The state Department of Transportation discounted the father's contention about an inoperable sign contributing to the crash.

"It doesn't matter how many signs in the world we put up -- and I don't want this to come across as insensitive -- or how far away we put them, if people are not watching and paying attention, it's not going to matter," said Christine Ouellette, a spokeswoman for the agency.

That said, the state has put up additional caution signs in both directions in the area since the collision. Ouellette noted that the patrol has seen a surge in crashes in the heavily traveled area, with 11 of 13 since April 1 involving serious injuries or death. "And the primary cause of all of those crashes was inattentive driving," she said.

Patrol Cmdr. Jeffrey Frenette said that reaching for something, using a cell phone, turning the dial of a radio, eating, talking or anything that takes a motorist's attention off the road can be a life-changing decision for the driver and others.

"We were all teenagers," Ouellette said, noting how the boys were distracted by the girl behind the wheel. "I can see that playing out in my head."

Goodrich's 22-year-old sister, Nicole, said Wednesday that trying to get the girl's attention while driving "sounds stupid, but how many times have we all done something like that. You're looking for a pen or a piece of paper, your phone rings and you reach for it. It happens every day, and [now] it happened to us."

The federal government is in the midst of national publicity campaign to combat distracted driving, which includes a "Faces of Distracted Driving" video series telling the stories of families that have been affected by what the U.S. Department of Transportation calls "this deadly epidemic."

In 2010, more than 3,000 people died in crashes nationwide involving distracted driving.

For more about the video series, visit www.distraction.gov/content/faces.

Like other states, Wisconsin limits the number of passengers young drivers can have in their vehicle. Zajec, however, was experienced enough behind the wheel to not be subject to such a limit.

Much of the small community 16 miles east of the Minnesota border has been in mourning since the crash. Hundreds of people turned out Sunday for a candlelight vigil at the high school's track bleachers for "a beautiful night and service with approximately 500 people coming together to share their support and comfort," said Principal Tom Wissink.

Cards, flowers and other mementos have been steadily gathering on a chain-link fence outside the school. Also, a website, ourfourboys.org, has been established to help the families with medical bills and memorial costs.

Services for Goodrich and Johnson have been held. Visitation for Zajec is scheduled from 4-7 p.m. Wednesday at Cullen Crea Funeral Home in New Richmond. Services are scheduled for Thursday at Immaculate Conception Catholic Church in New Richmond.

"These guys are the best," Taylor said. "All four honor roll students, all were athletic. . . . There are a lot of things that add up to an accident. They were taken at too young an age."

Paul Walsh • 612-673-4482