NEW YORK -- In what appears to be a stunning and heartbreaking coincidence, another fertility clinic said Monday its equipment temporarily failed, possibly damaging hundreds of eggs and embryos.

The incident at Pacific Fertility Center in San Francisco happened on the same day as a fertility clinic at Beachwood, Ohio-based University Hospitals Ahuja Medical Center. The level of liquid nitrogen in a cryo-storage tank used to preserve eggs and embryos dropped, raising the temperature in the tank and putting the eggs and embryos at risk.

Pacific Fertility Center is the second clinic to report equipment failure CBS News

Attorney Adam Wolf is now representing patients of Pacific Fertility Center who are planning to file a class action lawsuit this week.

"Never in their worst nightmares does that embryo become not viable because of conduct or misconduct of the clinic," Wolf said.

The clinic says they have thoroughly reviewed their storage equipment and protocols following the incident. They sent an email to patients who were affected, saying, in part: "While assisted reproductive technologies never come with guaranteed results, we are committed to exceptional patient care and to employing the highest quality practices in our laboratory."

"You don't even think about what's happening in the lab," said patient Katie Miller, a patient who has stored embryos stored at the center. "You just assume that that's being taken care of and not something to worry about it."