Kevin M. Ross, the president of Lynn University in Boca Raton, said the private contractor the school hired to help find the missing students had received "bad intelligence" earlier in the day when it told the school that the students had been located and taken to the airport in Port-au-Prince for transport out of the earthquake-ravaged city.
"This is hard news to deliver," he said. "But it is more difficult to hear for those family and friends with whom, only hours earlier, such good news had been shared. I am deeply sorry for that."
The students are Stephanie Crispinelli of Katonah, N.Y.; Courtney Hayes of Boca Raton, Fla.; and Britney Gengel of Rutland, Mass.
They were among 12 students and two faculty members traveling with the aid group Food For The Poor.
Eight of the students have been evacuated to the Dominican Republic after a 7.0-magnitude earthquake struck Haiti on Tuesday. Those eight were due in Fort Lauderdale early Friday. Ross said an anonymous donor provided a plane to bring them back from the Dominican Republic.
One other student, Christine Gianacaci, of Hopewell, N.J., remained missing, as did faculty members Patrick Hartwick and Richard Bruno.
The university said it has hired a second group of private contractors to join the search for its students and faculty members.
Hall said uncertainty remained about how the mix-up happened.
Earlier in the day, Gengel's father said he was shown a photograph provided by the searchers in Haiti that he believed showed his daughter.
Ross said it now appears that the woman was not his daughter.
"They are devastated by this news," Ross said. "They are still a very, very hopeful group."
Adding to the confusion is that seven of the students were reported safe at the U.S. embassy on Wednesday. Sometime since then, they were apparently joined by Melissa Elliott, of Hartland, Wis., who was reportedly found with the three women who are now unaccounted for.
Ross said there have not been any communications from any of the six people from the university who remain missing since the earthquake.
When they first heard their daughter, Julie, 21, was among the missing, Joan and Steve Prudhomme felt "pure terror and panic, actually," Joan told "Early Show" co-anchor Harry Smith from the family home in East Greenwich, Rhode Island on Thursday. "Your heart drops in your chest and you're desperate for any type of news. You have no idea what's going on, where she is, is she safe. And the group -- it's a feeling of unspeakable anxiety. We hope we never go through it again."
The U.S. embassy sent Steve and Joan an e-mail on Julie's behalf saying she's OK.
"We were ecstatic," Joan said. "A lot of tears, a lot of joy. But of course, that's all tempered with anxiety over the rest of the group -- we still have not received word about the remaining people."