DENVER -- Three drivers have been cited for driving too fast for conditions in the chain reaction crash that killed three members of a Denver family on Interstate 80 in Wyoming.

It happened Saturday near Rawlins. Fifty-nine-year-old John Parr, the founding direct of Colorado Common Cause who later advised mayors and governors, was killed along with his wife Sandra Widener, a co-founder of Westword, and their 19-year-old daughter Chase, 19. Their 17-year-old daughter, Katy, was the only survivor.

The Wyoming Highway Patrol said the roadway was icy and strong winds had created ground blizzard conditions, reducing visibility. The patrol said Parr lost control of his Subaru station wagon and his car slid around sideways on the road.

Two drivers that swerved to miss the Parr family and hit other vehicles were cited for driving too fast as was the driver of the tractor-trailer that broadsided their Subaru station wagon.

Family friends say Katy Parr is improving and could be released any day now.

In a written statement, Mayor John Hickenlooper and his wife Helen Thorpe said they cherished their memories of Parr, Widener and Chase.

"They made us better people. They made Denver a better city, and Colorado a better state. We struggle to comprehend this loss, and our hearts go out to Katy," they said.

Gov. Bill Ritter said he's been friends with the Parr family for nearly two decades. 

"There is no way to describe the pain of this terrible, terrible tragedy," Ritter said.  "This is such a devastating loss for the entire community on so many levels.  John and Sandy made untold contributions -- small, large and every size in between -- and touched untold lives.  They were loved by so many people that you can feel the tears ripple across Colorado today.  We will be in mourning for a long time."

Parr, the co-founder of Denver-based Civic Results, served as president of the National Civic League from 1985 to 1995 and was a board member of the Denver Downtown Partnership.

According to a biography posted on Civic Results' Web site, Parr directed the field organization to help elect Dick Lamm governor of Colorado in 1974 and, in 1983, served as the transition director for Denver Mayor Federico Pena.

Pena told 7News Parr had most recently worked for Denver A+, a community group that extensively studied the closure of several Denver Public Schools. Pena says Parr was about making government better.

"That was his love, that was his passion. It was Sandy's too, so they left an enormous mark in Denver and throughout state of Colorado."

Widener wrote for The Denver Post's Sunday magazine, Empire, and helped co-found the alternative weekly newspaper Westword and later worked as a freelance writer.

Chase was a sophomore at Wesleyan University who had a gift for singing, performing in "Fiddler in the Roof" in her senior year at East High School in Denver, said Parr's niece, Kathryn Pfaltzgraff McAllister of Newport News.

Katy is a senior at East, where she plays soccer, she said.

A candlelight vigil was held at Cheesman Park Sunday night. Many friends of Katy gathered to offer prayers and strength.

Parent Larry Dunn said, "It's just sad to think she's going to be alone except fo her aunts and her grandparents here in Denver."

McAllister said Parr and Widener were a team, united in their political views and intellectual pursuits. She said the historic bungalow where the family lived was always buzzing with plays and projects.

"They were people who lived life to the fullest," she said. "They got involved with their friends and neighbors and they knew what it took to make the world a better place. They thrived on helping other people."

The accident happened as the family was headed to Boise, Idaho to spend Christmas with Widener's parents and two sisters, McAllister said.

The highway patrol said there was blowing snow and icy conditions as Parr and his family headed westbound on I-80 in their 2007 Subaru station wagon.

First, their car slid and ended up sideways across the road, toward the median.

Angela Seeley, 42, of Colorado Springs, Colo. swerved her sport utility vehicle to avoid the station wagon but clipped its back. The station wagon, driven by Parr, was then hit by the tractor-trailer. That tractor-trailer was driven by William R. Bowers of Bremerton, Wash.

Seeley's SUV ran into the back of a snowplow driven by Johnny Frank Woolner of Rawlins, Wyo. A 2007 Chevy pickup driven by Robert Maxwell of Douglas, Wyo. avoided the station wagon but hit the SUV.

The crash is still under investigation.

Meanwhile, family and friends try to cope with the loss.

Steve Kadich has known Parr for more than 30 years.

Their daughters grew up together.

"I think more important that his public contributions were the kind of people that John and Sandy were and the kind of children they had," he said. "They were a caring, loving and open family. Friends always around their home, Sandy was a great cook. They were an incredible family, and a loss I think we're all trying to get our arms around."

Lamm said Parr was indispensable to his governorship.

"John was really one of those people who had broad shoulders and could handle any task you gave him," said Lamm. "There are things that are beyond comprehension, and to have a family close to wiped out is certainly one of them. They were good people and they will be sorely missed."