It looks like this for-profit college could be in financial trouble

Apollo Education Group, the parent company of The University of Phoenix, announced its second-quarter earnings this morning, and things don't look great for the for-profit college.

The company's shares fell 16% to $23.39, on news that total enrollments were down 15% and revenues were down 14%.

Apollo Chief of Staff, Mark Brenner, acknowledged the declining enrollment numbers and said that it was a challenging quarter and that certain changes should be made to improve the downward trend.

"I think what we've learned over the last couple of quarters we need to continued to invest in creating a better student experience, we need to have the best online classroom for students ... and we need to provide outsize value for students and align all of the curriculum and all of the teaching to career relevant outcomes for students," Brenner told Business Insider.

The decline in enrollments at The University of Phoenix is a continuing trend, as enrollment numbers have been cut in half from five years ago, down from 460,000 to 213,000, according to CNN Money.

Declining enrollment at the University of Phoenix, the largest for-profit university in the US, is potentially another signal of distress in the for-profit higher education sector. Last year, Corinthian Colleges, another major for-profit system, closed its doors amid legal action and accusations of financial manipulation towards students.