More than 10,000 critically endangered radiated tortoises were found in a Madagascar home, believed to be part of an illegal pet trade.

On April 10, police in Toliara, Madagascar found approximately 10,976 radiated tortoises in a private residency, according to San Diego Zoo Global (SDZG).

The house was described by SDZG as having nearly every one of its rooms covered with radiated tortoises.

Three days after police found them, hundreds had already died from dehydration and illness due to the severe lack of space and access to food and water in the home, SDZG reported.

The Turtle Survival Alliance (TSA), a group founded in 2001 to provide aid to species that are at a high risk of extinction, led a rescue mission in partnership with SDZG and other zoos to provide relief and recovery to these radiated tortoises.

“We were already caring for 8,000 tortoises in Madagascar—now that number has more than doubled overnight,” President of the TSA, Rick Hudson, said, “I don’t think the word ‘overwhelming’ comes close to describing what the TSA is dealing with here.”

The TSA has been relocating the radiated tortoises to a wildlife facility 18 miles north of the private residency, where SDZG experts and TSA staff have been providing care.

No information has been reported on who is responsible or for how long the radiated tortoises have been there, but local conservation law authorities have opened an investigation.

The radiated tortoises are believed to have been collected for illegal wildlife trafficking to Asia where their star-patterned shells are highly praised, according to SDZG, though nothing is confirmed at this time.

SDZG estimated that wild radiated tortoises have decreased by more than 80 percent in the last three decades. They believe the radiated tortoise could be extinct in the wild in less than 20 years.

The TSA has received support from the global conservation community with the understanding that every radiated tortoise saved may be the difference between the species’ long-term survival and its extinction, according to Kim Lovich, the curator of reptiles at the San Diego Zoo.