Hurricane Maria slams Dominica on Monday and it suffered "widespread damage" according to Prime Minister Roosevelt Skerrit.
The hurricane suddenly strengthened to a "potentially catastrophic" category five storm, before making landfall on the Caribbean island earlier this week.
Prime Minister Skerrit himself even posted live updates as his own roof was torn off, saying he was "at the complete mercy of the hurricane".
"My greatest fear for the morning is that we will wake to news of serious physical injury and possible deaths as a result of likely landslides triggered by persistent rains," he wrote after being rescued.
Hurricane Maria is moving roughly along the same track as Irma, the hurricane that devastated the region earlier this month.
It currently has the maximum sustained winds of 250km/h (155mph) and has been downgraded to a category four hurricane after hitting Dominica.
However, it could potentially increase again as it moves towards Puerto Rico and the Virgin Islands, according to forecasters. Furthermore, Dominica's PM called the damage "devastating" and "mind boggling".
"My focus now is in rescuing the trapped and securing medical assistance for the injured," he said, and called on the international community for help. "We will need help, my friend, we will need help of all kinds."
Meanwhile, the nearby island of Martinique has declared a maximum-level alert while another French island, Guadeloupe, ordered evacuations.
Meanwhile, hurricane warnings are in place for Guadeloupe, St Kitts and Nevis, Montserrat, the US Virgin Islands, the British Virgin Islands and Puerto Rico.
In Puerto Rico, the US territory expects Maria to make landfall as at least a category three storm later on Tuesday. It escaped the worst of Irma and has been an important hub for getting relief to islands badly affected by Irma. Governor Ricardo Rossello urged islanders to seek refuge if necessary.
In the US Virgin Islands and British Virgin Islands, both island chains suffered severe damage from Irma and President Donald Trump declared a state of emergency for the US territories on Monday. British authorities fear debris left behind by Irma could be whipped up by the new storm and pose an extra threat. The British government said more than 1,300 troops were staying in the region and an additional military team had been deployed.
Puerto Rico's governor, Ricardo Rosselló, has warned that Maria will have a much greater impact on the island than Hurricane Irma.
"It will essentially devastate most of the island," he warned on USA Today. He added: "It will provoke massive flooding in flooding prone regions ... our priority is to save lives."
