Carnegie Mellon University in Pennsylvania accidentally admitted about 800 applicants to their master's program in computer science on Monday, the Associated Press reported.

The school's computer science department computers generated and mistakenly sent out congratulatory letters to college hopefuls.

"You are one of the select few, less than 9 percent of the more than 1,200 applicants, that we are inviting," it read, according to The Post-Gazette. "We're convinced this is the right place for you. Welcome to Carnegie Mellon!"

Seven hours later, they received heartbreaking follow-ups that their admissions had been in error.

"It was brutal. I didn't get much sleep last night," Ben Leibowitz, of Stamford, Conn., told the AP Tuesday after he called up relatives telling them in got into the school's prestigious graduate computer program. "Now I have to clean up the mess. I'm calling all my relatives, I'm going, 'I'm sorry it's not happening.'"

Kenneth Walters, spokesman for Carnegie Mellon, said the "Welcome to Carnegie Mellon!" emails were the result of "serious mistakes" that "incorrectly flagged" students for admission. He said the school would conduct a review to prevent another error.

"We understand the disappointment created by this mistake, and deeply apologize to the applicants for this miscommunication. We are currently reviewing our notification process to help ensure this does not happen in the future." Walters said in a statement.

Carnegie Mellon University's computer science graduate program is ranked number one in the country by the U.S. News & World Report.