Their own daughter, it turned out, was dead and buried.
In a tragic mix-up, one family had been incorrectly told their daughter had died in the April 26 crash in Indiana, and another was erroneously informed their daughter was in a coma.
The two young women - both students at Indiana's Taylor University - looked remarkably alike, and the one in a coma suffered facial swelling, broken bones and cuts and bruises, and was in a neck brace.
The family of Laura VanRyn, 22, disclosed the mix-up Wednesday on a Web log that they had used to record detailed updates on the young woman's recovery.
"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, but instead a fellow Taylor student of hers, Whitney Cerak," the VanRyns said on the blog.
The family said that as the young woman began regaining consciousness at a rehabilitation centre in Grand Rapids, Mich., she said things that made them question her identity.
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."
In a statement, the two families said they took their concerns to hospital officials, and dental records confirmed that the injured woman was Whitney Cerak.
Officials at Taylor University, an evangelical Christian college in Upland, Ind., about 100 kilometres from Indianapolis, confirmed the case of mistaken identity.
"We rejoice with the Ceraks. We grieve with the VanRyns," said Taylor spokesman Jim Garringer. He said the Grant County coroner notified the school of the error.
Four Taylor students and an employee were killed when their van was struck by a tractor-trailer that had drifted across a highway median. Those in the van worked for Taylor's dining services and were preparing for a banquet for the inauguration of a new president of the 1,850-student school.
It was not clear who mistakenly identified the victims or how the error happened. The coroner's office did not immediately return a call. But the VanRyns, who are from Caledonia, Mich., said their daughter and Cerak, 18, of Gaylord, Mich., bore an "uncanny resemblance."
Most of the crash victims had funerals with closed caskets. A month ago, an overflow crowd of more than 1,400 people turned out for what they thought was Cerak's funeral in Gaylord, Mich.
The VanRyn family used the blog to provide progress reports on the young woman, reporting, example, that her hair was in pigtails or braids, that she managed to feed herself some applesauce, that she played a game of "connect four" with one of the therapists and did quite well, and that she performed an exercise in which her therapist gave her a word and she had to supply the word's opposite.
A call to the VanRyns was not immediately returned. A lawyer for the Cerak family did not return a call either.
Prosecutors are weighing criminal charges against the truck driver, saying he may have fallen asleep at the wheel.