Lawyers have filed an emergency bill of discovery to investigate what went wrong.
The men, who are 26, 33 and 48 years old, all suffer from illnesses or had to undergo medical treatments that left them infertile.
Their attorney, Matthew Jenkins, says all three may have lost their only chance to have a child.
"This is absolutely unforgiveable," said Jenkins. "These families have lost the opportunity to have children of their own, and we believe they're entitled to answers."
The Northwestern Medical Faculty Foundation released a statement admitting that a storage tank malfunctioned and that it regrets that it occurred.
It says in many cases, samples are still viable for in-vitro procedures.
