Maria has made landfall in southeastern Puerto Rico as a Category 4 hurricane this morning.
In advance of the storm's arrival, the territory's governor warned that Maria was going to be an ``extremely violent phenomenon.''
Zinc roofs were already flying and windows were breaking as Maria approached Puerto Rico before dawn, with nearly 900,000 people without power and one tree falling on an ambulance.
Those who sought shelter at a coliseum in San Juan were moved to the building's second and third floors.
Maria ties for the eighth strongest storm in Atlantic history, by wind speed.
It's second only to Irma, which had 300 kilometre per hour winds and killed 38 people in the Caribbean and another 36 in the U-S earlier this month.