Apparently, the Hartford, CT Mark Twain House & Museum contains an amazing collection of artifacts collected by Samuel Clemens throughout his life. Sadly, however, much of that collection has been threatened by mold growth caused by a faulty HVAC system.

According to Susan Dunne of the Hartford Courant:

In November 2015, mold was found in the storage facilities of the historic home’s museum center, tainting at least 5,000 of the museum’s 16,000 artifacts. The vulnerable pieces are varied: 19th-century furniture, upholstery, metal, glass and leather items, as well as books, including some Twain first editions and translations, whose fabric and leather bindings are conducive to mold growth. The spread of the mold has been halted for the time being — the HVAC system has been repaired and the archive’s relative humidity is being carefully monitored — but the task remains to remove the mold that already is there…

More specifically, the cause was related to a rather sophisticated geothermal heat pump system designed to use substantially less energy than more traditional HVAC systems.

“The motors in the geothermal wells that moderate the temperature in the building would break down regularly,” Lamarre said. “One of the wells malfunctioned, causing enormous pressure to build up in the system. The pipes in the mechanical room burst in multiple places, causing water to flood down the back hall of the museum center. The auditorium was flooded with a foot and a half of water.”

“The explosion of the geothermal well led to an increase in the humidity problem in the building at large because the decision was made to cap the wells instead of repairing them,” he said.

This isn’t the first time the historic home and museum has faced operational issues, however. From 2002 through 2010, a former employee of the organization embezzled more than $1-million. In 2008, the organization laid off 33 of its 50 employees following a financial restructuring.