The Hockaday School educates some of the wealthiest families in Texas. The all-girls school has taught girls with last names like Bush and Cuban.

For 30 years, Kifleab Tekle helped protect those girls.

>> Read more trending stories

"He's the one who broke his arm chasing after someone who was trying to break into a building," recalled Amy Patrick on a GoFundMe page. "If you've ever been to Hockaday, you've seen Kief. He's the one who knows your name, even after fifteen years away from campus."

When the alumnae learned their beloved security guard was retiring, they started a GoFundMe page to raise money for a retirement gift. So far, the account has raised more than $180,000.

"He kept us safe," Patrick told the Dallas Morning News. "And he fought for safety."

The girls remember bringing him treats in the morning. They say he had a sharp memory, remembering the names of their parents and siblings long after they had graduated.

At a retirement party for Tekle, the alumnae presented him with the cash. They also gave him a book that contained 1,700 comments from his former students, who fondly recalled memories of their favorite security guard.

“I am speechless,” Tekle said. “I love you.”