LOUISVILLE, Ky. (WDRB) -- Eastern High Senior Anna Applegate went into Christmas break with a bit of a heavy heart.

"He gave us the news the Friday before last, and all of us are super upset," Applegate said.

Her math teacher, Joseph Kimeu, won't be back when students return to class in January. 

"You could never tell," she added. "He's like the happiest little man alive."

Not because he has a better opportunity at some other school, or he's retiring, but because his VISA is not being renewed. 

Going back to Kenya is his only choice.

"He works so hard," Applegate said. He has his family with two young kids. One of them is not even a year old."

Applegate took it hard. She wrote an open letter of sorts on Twitter with 574 retweets, 864 likes and several responses:

"I mean, he knows that we care about him, and he cares about us. It's hard to see," Applegate said.

The hardest part may be the fact that no one knows for sure why it's happening.

"He did say it wasn't in my hands," Applegate said. "It was simply someone else's mistake."

JCPS' Human Resources Department sent WDRB a statement about it. It says each individual works with an attorney and the employer to provide documentation for renewal. 

It goes on to read, "since the new HR person's involvement in the case, applications have been filed appropriately."

JCPS says the first VISA was denied, and the second was pulled for an audit, which they claim is no one's fault and is also not that unusual.

As for Applegate, she was forced to say her goodbyes to a teacher who will have always made a difference in her life, no matter the distance that will soon separate them.

"He's just a great teacher," she said. 

The district tells us Kimeu is expected to return to the classroom in the fall.

Copyright 2016 WDRB Media. All Rights Reserved.