Talk about a brain freeze -- or lack thereof.

A freezer malfunction at Harvard-affiliated McLean Hospital in Belmot, Mass. has severely damaged one-third of the world's largest collection of autism brain samples, potentially setting back research on the disorder by years, scientists say. An official at the renowned brain bank in Belmont discovered that the freezer had shut down in late May, without triggering two alarms. Inside, they found 150 thawed brains that had turned dark from decay; about a third of them were part of a collection of autism brains.

A total of 93 donated brains were damaged, 54 of them earmarked for autism research through Autism Speaks, according to a report by ABC News.

Harvard spokesperson, Adriana Bobinchock, said an investigation to determine how the freezer failure occurred is underway, according to the report. After reviewing surveillance footage, Bobinchock said foul play is unlikely.

It's still unclear whether the brains are permanently damaged, Bobichock said.

An open letter from the organization's Chief Scientific Officer Dr. Geri Dawson wrote that the organization is confident the organization can continue in its scientific studies "based on brain tissue."

More than 3,000 donated brains remain in the Brain Bank's collection. It is the largest and oldest federally-funded brain bank in the United States.

Dr. Francine Benes, director of the organization, told the Boston Globe that the freezer was estimated to have been off three days before anyone noticed.

The newspaper reported that the Brain Bank had been collecting brains from people with autism for approximately 20 years and it will likely take several more years to replace the damage.