For 20 years, a Rensselaer Polytechnic Institute professor had been working on what the university described as potentially groundbreaking work.

It all ended with the accidental flip of a switch.

The university is seeking $1 million in damages from Daigle Cleaning Systems in Albany, N.Y., for breach of contract and for failing to properly train a janitor who turned off a circuit breaker in September 2020, cutting power to the freezer and destroying its contents, according to a lawsuit filed this month in Rensselaer County Supreme Court.

The janitor, Joseph Herrington, said in a deposition that he had become concerned because “annoying alarms” were coming from the freezer and he worried that “important breakers” had been turned off. But instead of turning them to the “on” position, the lawsuit says, he had turned them off.

In the lawsuit, which was reported by The Times Union of Albany, Rensselaer said Mr. Herrington “is a person with special needs,” but the university accused his employer of not providing adequate training on “how to handle specialized and delicate equipment.”

Rensselaer and the cleaning company did not immediately respond to requests for comment.

It was unclear what kind of research was being conducted in the lab, but according to the lawsuit, the work was overseen by K.V. Lakshmi, a professor and the director of Rensselaer’s Center for Biochemical Solar Energy Research. According to the lawsuit, Dr. Lakshmi was conducting “high level research” inside the Cogswell Laboratory building on the university’s campus in Troy, N.Y. The lab included a freezer that housed cell cultures and samples that had to be kept at minus 80 degrees Celsius (minus 112 degrees Fahrenheit).

A small temperature fluctuation of even just a few degrees would “cause catastrophic damage and many cell cultures and samples could be lost,” the lawsuit said. As a precaution, an alarm would sound if the freezer’s temperature increased to minus 78 degrees or decreased to minus 82 degrees.

On Sept. 14, 2020, when the freezer’s temperature rose to minus 78, the alarm sounded. Dr. Lakshmi and her staff “began taking action immediately to address the cause and to protect the cell cultures, samples and research,” the lawsuit says. The cell cultures and other samples were not harmed at the time, and Dr. Lakshmi contacted the freezer’s manufacturer to schedule an emergency service. But because of Covid-19 restrictions, the freezer could not be serviced immediately, according to the lawsuit.

As the alarm continued to sound, Dr. Lakshmi installed a safety lock box on the freezer’s outlet and socket with a note in capital letters that said that it should not be moved or unplugged and that no cleaning was required. She added instructions for how to mute the beeping, the lawsuit said.

Days later, on Sept. 17, Mr. Herrington, who was assigned to clean the lab, turned off the circuit breaker to the freezer, causing the freezer to shut off and its temperature to rise to minus 32 degrees Celsius.

In his deposition, Mr. Herrington said the alarms continued throughout the evening. He said he looked at the electrical box and consulted a guide to the breakers. Mr. Herrington said he believed the breakers to the freezer were off and he “turned them back on to make sure he was helping to safeguard the equipment,” according to the lawsuit. The suit says he knew “how important the breakers were because his father works in plant/utilities at another college.”

But Mr. Herrington had misread the breaker guide. Instead of moving the breakers to the “on” position, the lawsuit says, he moved them to the “off” position at about 8:30 p.m.

“He did not believe he had done anything wrong but was just trying to help,” according to the lawsuit.

Graduate students discovered the next day that the freezer’s contents could not be saved, the lawsuit says.

“A majority of specimens were compromised, destroyed, and rendered unsalvageable,” the lawsuit stated, “demolishing more than 20 years of research.”