They were together the night of April 26, returning from banquet preparations with a group from Taylor University, when a tractor-trailer slammed into their university van, peeling off the side and killing five people.
Cerak's family was told their 18-year-old was among the dead. VanRyn's parents were told their 22-year-old daughter was alive but seriously injured and in a coma.
The VanRyns kept vigil at the young woman's bedside for weeks, but as she gained consciousness, she began saying things that didn't make sense. This week, they discovered that the recovering patient wasn't their daughter at all. She was Whitney Cerak.
"I still can't get over it. It's like a fairy tale," said Cerak's grandfather Emil Frank. "It's just so unbelievable. But we feel just as much for the family that found out it was not their daughter."
VanRyn's parents, who had kept a daily Web log of the young woman's recovery after the crash, disclosed the mix-up on the blog.
"Our hearts are aching as we have learned that the young woman we have been taking care of over the past five weeks has not been our dear Laura," the family wrote.
Cerak's face was swollen after the crash, she was in a neck brace, and she had brain damage, broken bones and bruises. The Grant County, Ind., coroner said that the accident scene had been strewn with purses, and that students had identified the survivor as VanRyn. No scientific testing was conducted to verify the identities.
"I can't stress enough that we did everything we knew to do under those circumstances, and trusted the same processes and the same policies that we always do," said Coroner Ron Mowery. "This tragedy unfolded like we could never have imagined."
In Cerak's hometown of Gaylord, in northern Michigan, her family held a closed-casket funeral that drew 1,400 people.
VanRyn's family, meanwhile, detailed the many small steps they believed their daughter was making toward recovery at a rehabilitation center in Grand Rapids: feeding herself applesauce, playing Connect Four with a therapist.
As recently as Monday, the VanRyns reported: "While certain things seem to be coming back to her, she still has times where she'll say things that don't make much sense."
Mowery said VanRyn's boyfriend initially questioned her identity based on the young woman's behaviors and comments. Then VanRyn's father became suspicious when she referred to him by a pet name he didn't recognize.
"He started asking questions and the process evolved to where she actually came to and suggested who she was and wrote her name," Mowery said.
When relatives took their concerns about the young woman's comments to hospital officials, dental records confirmed the injured woman was actually Cerak.
"Both families understand how this could have happened," said Bruce Rossman, a spokesman for Spectrum Health, which operates the rehab center.
In a joint statement, the VanRyn and Cerak families said the two young women shared a "striking similarity in appearance."
"Our families are supporting each other in prayer, and we thank our families, friends and communities for their prayers," the statement said.
Officials at Taylor University, an evangelical Christian college in Upland, Ind., about 60 miles northeast of Indianapolis, confirmed the case of mistaken identity.
"Certainly there are those people that are devastated today because the person, their friend, who they thought had lots of hope and was progressing every day — they now found out she has died," Taylor student body president Brent Maher said in a televised interview. "There are also those who are rejoicing because Whitney is alive."
Word of the mix-up also circulated at Gaylord High School, said Cerak's volleyball coach, Jen Mazza.
"I don't know what to feel right now. You're elated but you almost don't want to trust it," Mazza said. "Right now we just want to get her home and see her for ourselves. ... Everyone who was touched and grieving for Whitney will be grieving for the other family. We've been there."
Joe Sereno, associate pastor at Gaylord Evangelical Free Church, said what had been thought to have been Cerak's casket had been closed both for visitation and for the funeral.
"We did everything you usually do," Sereno said. "We had a memorial service at the church. The family did a private burial the next day. Everybody thought it was Whitney."
Telephone messages were left Wednesday and Thursday for the VanRyns and Ceraks. A young man outside the VanRyns' home declined a reporter's requests for comment Thursday.
On Wednesday evening, a steady stream of cars came and went from the VanRyns' house in Caledonia, a village about 20 miles southeast of Grand Rapids. A memorial service for VanRyn is scheduled Sunday near Grand Rapids.