A dam failure has caused “extremely dangerous” flooding on a Puerto Rico river in the wake of Hurricane Maria, authorities say.
The National Weather Service (NWS) said the failure of the Guajataca Dam is a “life-threatening situation”.
More than 70,000 people live in the nearby towns of Isabela and Quebradillas.
At least 13 people have died since Maria ripped through Puerto Rico, knocking out power to the whole island.
Operators of the Guajataca Dam said the structure, at the northern end of Lake Guajataca in northwest Puerto Rico, failed at 14:10 local time (18:10 GMT).
It sparked a flash flood emergency for Isabela and Quebradillas municipalities, the NWS said in a series of tweets.
The agency urged residents in the area to “move to higher ground now” in an alert posted on its website.
Many who live near the dam are being evacuated by buses.