Two hundred hikers had to be evacuated from the Grand Canyon via helicopter Thursday after two powerful weather systems unleashed a torrential downpour in Arizona.

The rescue of the hikers took place in the remote Havasu Falls area of the Grand Canyon, which is part of the Havasupai Indian Reservation. The sudden flash flood sent tourists scrambling up trees and into caves as they sought higher ground.

The area is expected to remain closed for 7 to 10 days due to the severe flooding.

Tourist Benji Xie said people were swimming at the base of waterfalls when the flash flooding struck, sending them scrambling for higher ground:

“The sky opened up. Winds started blowing, sand was blowing everywhere and rain was coming down in sheets,” he told The Associated Press.