ATLANTA — A billionaire has promised to set up a grant to pay off the student debt of nearly 400 students from the Morehouse College graduating class of 2019.

Robert F. Smith — a billionaire investor estimated to be worth $5 billion by Forbes — was this year's commencement speaker. His gift to the graduating class? A grant to pay off their student loans. That's 396 young graduates.

In the live Facebook video shared by Morehouse College, you can hear students erupting into celebration and professors behind Smith go wide-eyed after he announced the surprise in the last few minutes of his speech.

Before breaking the news to the class, Smith told the students, "we're gonna put a little fuel in your bus." That little fuel will go a long way for many.

According to the Associated Press, finance major, Aaron Mitchom was going to graduate with a $200,000 student loan. Smith's grant will allow him to step out of college debt-free. He told the AP, "I was shocked. My heart dropped. We all cried. In the moment it was like a burden had been taken off."

Student loan debt in America is on the rise. According to a report by the Institute for College Access and Success, in 1996 college seniors in four-year programs had an average debt of $12,750. That number has increased to $28,650 as of 2017.

Smith's donation is all the more impactful because Morehouse is a predominantly African-American college.

According to a report by the Brookings Institution, African-American college graduate students owe $7,400 more than white students. Their debt grows to almost $53,000 four years after graduation. That's double the amount of white students.

This isn't Smith's first contribution to Morehouse. In January, he donated $1.5 million to fund scholarships and created an outdoor study area for` the students. Imagine if the rest of the 1 percent did stuff like this regularly?