For more than a month, Laura VanRyn's friends and relatives thought she had survived a van crash that killed five people, and they celebrated the young woman's milestones as she recovered.

Then came the stunning news last week of a tragic mix-up: It was not VanRyn, but a college classmate who had survived in a coma-like state. On Sunday, friends and relatives gathered to remember VanRyn, a 22-year-old senior who was just weeks shy of graduation.

"She brought more joy to us than we could ever imagine," her older brother, Kenny VanRyn, told the nearly 2,000 people who gathered at the memorial service at Kentwood Community Church.

VanRyn's family planned to exhume her body, which was buried April 30 under a tombstone with classmate Whitney Cerak's name.

"This week, we were introduced to a concept that can only be called retroactive grieving," the Rev. Andy Smith said at a church service earlier Sunday at Forest Hills Bible Chapel in Caledonia, the VanRyn family's congregation.

Members of Cerak's family, however, "have experienced a resurrection of sorts, and we can rejoice with them," Smith said.

About 180 miles to the north, in Cerak's hometown of Gaylord, about 1,000 worshippers listened Sunday as the Rev. Jim Mathis described the reunion between Cerak and her parents after the mistake was discovered.

"It was just joy and tears and hugs," Mathis said at Gaylord Evangelical Free Church. "I saw a small glimpse of heaven — the child being reunited in the arms of the heavenly father."

Cerak, 19, who bore a strong resemblance to VanRyn, was in a coma after the van she and other students from Taylor University were riding in was hit by a tractor-trailer April 26. Her face was swollen, and she had broken bones, cuts and bruises.

VanRyn's parents did not begin to question whether she was actually their daughter until, as she regained consciousness, she started saying things that did not make sense to them, including referring to VanRyn's father by a pet name he did not recognize.

She replied "Whitney" several times after VanRyn's parents addressed her as "Laura," Anne Veltema, a spokeswoman with Spectrum Health in Grand Rapids, said last week. Dental records confirmed the mix-up Wednesday.

The Ceraks, who have started posting updates about Whitney on a Web log started by VanRyn's relatives, said Whitney has been sitting up and talking.

"Some of her friends came for short visits and she would greet each with a hug and was able to hold conversations with great interaction," Carly Cerak, Whitney's sister, wrote in the online journal.

A speech therapist "has begun to walk her through the events of the past five weeks," Carly Cerak wrote. She said her sister listened and nodded her head.

The news of the mistaken identity stunned VanRyn's loved ones, including her boyfriend of three years, Aryn Linenger. He said Sunday he never doubted that the woman in the hospital bed was VanRyn.

"I saw her hands, her feet, her complexion, and I can't believe that it wasn't her," Linenger said. "Even to this day, it's amazing to me that with all that time we spent together, that I just didn't know."