The Guajataca Dam in Puerto Rico failed Friday afternoon, causing flash flooding in the area, the National Weather Service reported.

“This is an EXTREMELY DANGEROUS SITUATION,” the NWS in San Juan tweeted. “Busses are currently evacuating people from the area as quickly as they can.”

Operators reported that the dam, which is on the northern end of Lake Guajataca, was failing at 2:10 p.m., causing flash flooding downstream.

Puerto Rico is still reeling from Hurricane Maria, which cut power to the entire island after it made landfall Wednesday as a Category 4 storm.