Puerto Rico’s governor declared a state of emergency on Tuesday after a powerful 6.4 magnitude earthquake killed at least one person in the south of the island and caused widespread damage.
Governor Wanda Vazquez said the declaration would allow for the activation of National Guard troops in the US territory still recovering from a devastating 2017 hurricane.
The US Geological Survey said the quake struck at 4:24 am (0824 GMT) with the epicentre off the coast of the southern city of Ponce, and was followed by more than a dozen aftershocks.
Tuesday’s quake was the most powerful in a series of tremors that have shaken the island since December 28.
Scientists initially sent out an alert about a potential tsunami but it was later cancelled.
The island’s electricity authority said the quake had forced an automatic shutdown of the power grid, already severely damaged by Hurricane Maria more than two years ago.
The worst damage appeared to be in towns on the southwest coast, including Ponce, Guayanilla and Guanica.