Image copyright Getty Images Image caption Floodwaters from Hurricane Maria have destroyed homes in Puerto Rico and knocked out the island's electricty
A failing dam is causing "extremely dangerous" flooding on a Puerto Rico river in the wake of Hurricane Maria, authorities say.
The National Weather Service (NWS) said the "imminent failure" of the Guajataca Dam is a "life-threatening situation".
More than 70,000 people live in the nearby areas 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, began to show signs of failing 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.
Maria, a category three storm, is now moving away from the Turks and Caicos Islands.
It is expected to head to the northeast and east of the Bahamas over the weekend, forecasters say.
Puerto Rico's governor has called Maria the worst hurricane in a century.
Ricardo Rossello says it could take months to restore electricity to all 3.4 million of the US island territory's residents.
Roofs were ripped off as 140mph (225km/h) winds battered Puerto Rico's capital city, San Juan.
Media playback is unsupported on your device Media caption Where has Hurricane Maria hit?
The hurricane has claimed more than 30 lives across the region, and is the second devastating storm to hit the Caribbean this hurricane season.
The first was category five Irma earlier in September.
Maria also caused widespread destruction on the small island of Dominica when it hit on Monday night, leaving at least 15 dead and 20 missing.
US President Donald Trump has pledged to visit Puerto Rico, saying it was "totally obliterated" by the storm.
He has yet to declare the island a disaster area, but has made federal emergency aid available.
here-come-the-toes on September 22nd, 2017 at 23:19 UTC »
Thread title says "dam bursts" but the news article says it bursting is "imminent"
TooShiftyForYou on September 22nd, 2017 at 20:50 UTC »
The National Weather Service tweeted “This is an EXTREMELY DANGEROUS SITUATION. Buses are currently evacuating people from the area as quickly as they can,” and then an hour later “All Areas surrounding the Guajataca River should evacuate NOW. Their lives are in DANGER! Please SHARE!”
Scary stuff and best wishes to all affected.
https://twitter.com/NWSSanJuan
XSC on September 22nd, 2017 at 19:36 UTC »
Maybe this will make enough news so people can actually know how fucked we are? There are still municipalities with no communication. The south is still cut off. 15 are dead but I fear that number will be higher. No power, 95% of communications are destroyed or off. People are underwater in some places. Landslides everywhere. The infrastructure is a mess. Even concrete electric poles were knocked down. We need help people. This wasn't just a small part of the island, it's the WHOLE ISLAND. These are American citizens trapped there.
Edit: Please stop making these threads about trump, citizenship or other things. We don't care about any of this for now. We just need help.
If you want to donate Here is a link DIRECTLY TO THE PUERTO RICAN GOVERNMENT http://unidosporpuertorico.com/en/ This was set up by the governor and first lady
USVI is also getting help by Coast Guard, military and FEMA. Comms are still cut off to south of PR and central PR. Gov. Cuomo was in PR today.
/u/eckeypair has an update regarding help https://www.reddit.com/r/news/comments/71ta4z/mass_evacuation_as_puerto_rico_dam_bursts/dndm077
Video of dam collapse http://www.noticel.com/noticia/208280/todos-los-recursos-al-oeste-para-desalojar-poblacion-cercana-a-rio-guajataca.html
We are all grateful for the help!