Alyssa was in her high school health class around midday Wednesday when she got the email welcoming her to Tulane University and giving her a college email address. In a grueling college admissions season, it was her first-choice university, and she had applied early decision, meaning she was committed to the place.

Excited by the news, Alyssa texted her mother, told many of her classmates and was congratulated by one of her favorite teachers, a Tulane alum. But two or three hours later, she received a second, decidedly more downbeat email telling her it had all been a mistake.

"It felt crushing," she said Friday. "It was my dream school."

Alyssa was one of 130 applicants who received emails that day from Tulane, a highly selective school in New Orleans, beginning, "I am pleased to welcome you to Tulane!" They were quickly followed by a retraction email and a rather abject public apology headed, "We Messed Up," from the university's admission director. Alyssa asked not to be fully identified because she was humiliated and did not want to be associated with what she called a scandal.

Students and parents, already full of anxiety over the high-stakes admissions process, expressed their disbelief and agony online.

The torrent of recriminations came as universities across the country have been promoting their brands this week by announcing their early admissions results. Each new class, they boast, is their best crop of students ever from their biggest ever pool of applicants.

Some students and guidance counselors suggested that the only honorable course for Tulane would be to admit all 130 students, though Tulane indicated that the almost-enrollees would receive no special consideration.

Tulane's defenders were quick to point out that it is not the first university to have made such a mistake. Some of the most prestigious institutions of higher education in the country, including MIT, Carnegie Mellon, Vassar, UCLA, Fordham, Johns Hopkins and the University at Buffalo, have sent out misfired admissions notices in recent years.

The confusion also points out the intricacies of the college application process, with its multiple deadlines and conditions worthy of a real estate contract. The mistake happened with candidates for early decision, which generally gives an applicant better odds of getting in.

A student can only apply early decision to one college and must commit to attend if accepted. Applications are usually due in November rather than the usual January deadlines, and acceptances are sent in December rather than March.

"These kids are already so anxious, and the whole process has become so crazy, so this is really a horrible, horrible thing to put them through," said Phillip Trout, a college counselor at Minnetonka High School in Minnetonka, Minnesota, and past president of the National Association for College Admission Counseling. "But I also feel really bad for the admissions offices when this happens. It's got to be just turning them upside down. Here's what's supposed to be a big moment for them, and it turns into a disaster."

The mistake has eclipsed any happier admissions announcements Tulane might have issued. Dartmouth, for instance, said it had admitted 555 students early decision to the class of 2021, out of 1,999 applicants, the biggest early decision pool in its history. They came from California to Vietnam and had "farmed blueberries, managed bluebird conservation areas and designed shoes for Nike," the announcement boasted.

Duke also trumpeted its record-setting number of early decision applicants, and Harvard said it had the lowest acceptance rate for early applicants since reinstating the program in 2011. The University of Pennsylvania, meanwhile, declared that its early decision pool was the largest in its history, reflecting "a greater breadth of interest in Penn" from applicants far and near, rich and poor, male and female.

At Tulane, meanwhile, Jeff Schiffman, the admission director, weighed in on his blog: "Yesterday, we made a mistake," he said, adding: "We've created an anxiety so deep for this group that there really aren't words to describe it. I'll own up to it right now."

The ultimate Tulane class of just over 1,700 students will not be decided until later. Bob Dannenhold, a private admissions counselor in Seattle, suggested that if Tulane really wanted to show remorse, "They can put these kids in a special pile and give them every possible consideration in the process."

Schiffman acknowledged in his blog that "in a perfect world, that would be true." But admitting all of them, he said, "greatly throws off the size of the class. It simply can't be done."

Mike Strecker, a spokesman for Tulane, said Friday that the misfired emails were the result of a "technical error" and that although "it is quite understandable that some students receiving this message would infer that it was an offer of admission to Tulane, no such decision had been made in the case of these students."

The university's explanation was complicated and blamed new software. True offers, Strecker said, come from the Office of Admission. When a student accepts the offer and makes a deposit, that triggers the type of message, from Technology Services, that the 130 students received, with instructions on how to set up a Tulane email account. "Due to a coding error in how we installed new software, our system mistook deferred students for deposited students," he said.

He said some of the 130 students had been offered admission for the spring of 2018 term rather than starting next fall. Others would be deferred and considered as part of the regular pool.

Strecker said Tulane had received 22,256 early admission applications and admitted 6,480, or 29 percent, down from 35 percent last year. Last year's regular admissions rate was 7 percent.

Sally Rubenstone, senior adviser at College Confidential, an online forum where students and their parents exchange information and tips, said in an email Friday that her own son was a sophomore at Tulane. "We all felt that the Tulane staff treated him like an individual and not a commodity!"

Despite the pain, she continued, "I also hope that parents will help their progeny to put this mistake in perspective. As I posted on the thread myself, 'If it had been my child who'd received false hope, I'm sure I'd be sad and angry, but I would've also realized that he'd be learning a good lesson about life's curve balls.' "

A doctor in Pennsylvania, the father of one of the 130 students, who asked not to be identified for fear of jeopardizing his daughter's application, said his daughter had driven 100 miles to be interviewed by a Tulane student, and had been poised to turn down several other colleges that had already accepted her.

Now, he said, "she has been put on regular decision, thrown back into the mix."

Alyssa said she had been admitted to the spring 2018 term, a semester later than she had hoped. "I don't know if that's like a consolation prize," she said.

But she said she still felt bad for the other students who have been on the same roller coaster of emotion. "I understand that accidents happen," she said. "I think they ought to save space for the regular admissions pool by 130, and then just let these kids in."