A parking lot is flooded in San Juan, Puerto Rico, as Hurricane Maria hit the island on Sept. 20, 2017.

Maria was the first Category 4 hurricane to make landfall in Puerto Rico since 1932.

A man rescues a rooster from his flooded garage in Fajardo after Hurricane Maria hit Puerto Rico, Sept. 20, 2017. 

Trees are toppled in a parking lot at Roberto Clemente Coliseum in San Juan, Puerto Rico, on Sept. 20, 2017, during the passage of the Hurricane Maria.

Rescue workers help people in Guayama, Puerto Rico, after the area was hit by Hurricane Maria. Power was knocked out across the island.

A destroyed house lays flooded in Catano town, in Juana Matos, Puerto Rico, on Sept. 21, 2017, after being pummeled by Hurricane Maria.

Debris from a destroyed bar in Fajardo, Puerto Rico, after Hurricane Maria made landfall on Sept. 20, 2017.

Residents of San Juan, Puerto Rico, look out at damage caused by Hurricane Maria.

"Once we're able to go outside, we're going to find our island destroyed," said Abner Gomez, Puerto Rico's emergency management director. 

Damaged homes from Hurricane Maria are shown in this aerial photo over the island of Dominica, Sept. 19, 2017. 

A series of Facebook posts by Dominica Prime Minister Roosevelt Skerrit captured the fury of the storm as it made landfall on the mountainous island: "The winds are merciless! We shall survive by the grace of God," Skerrit wrote.

A dog looks out of a house flooded by Hurricane Maria, in Catano town, Juana Matos, Puerto Rico, on Sept. 21, 2017. The hurricane devastated the island and knocked out the entire electricity grid. 

Damage is seen in the La Perla neighborhood of San Juan on Sept. 21, 2017. The area's colorfully painted houses became famous as the setting for the music video of "Despacito."

Cars drive through a flooded road in the aftermath of Hurricane Maria in San Juan, Puerto Rico, on Sept. 21, 2017. Puerto Rico Governor Ricardo Rossello called it "the most devastating storm in a century."

Flooding is seen after Hurricane Maria hit Fajardo, Puerto Rico, on Sept. 20, 2017. 

The NASA Day Cloud Convection RGB uses multiple bands to help discriminate liquid/low clouds (yellow) from ice/high clouds (white)  in this satellite image of Hurricane Maria.

Rescue workers pray before walking out from the Emergency Operation Centre in Guayama, Puerto Rico, on Sept. 20, 2017.

People are transported down a road flooded by Hurricane Maria in Catano, Puerto Rico, on Sept. 21, 2017. 

Hurricane Maria batters Fajardo, Puerto Rico, on Sept. 20, 2017.

Hurricane Maria blows ashore in San Juan, Puerto Rico, on Sept. 20, 2017.

Rescue team member Jonathan Cruz cries on the floor as he waits to assist in the aftermath of Hurricane Maria in Humacao, Puerto Rico, Sept. 20, 2017.

Residents of San Juan, Puerto Rico, get a first look at damage from Hurricane Maria. The storm knocked out power across the U.S. territory.

A man wades through floodwaters in Fajardo after Hurricane Maria slammed Puerto Rico, Sept. 20, 2017. 

Rescue workers help a woman to get into the Emergency Operation Centre  in Guayama, Puerto Rico, after Hurricane Maria, Sept. 20, 2017.

A resident surveys the damage on her property after Hurricane Maria made landfall, in the Guaynabo suburb of San Juan, Puerto Rico, Sept. 21, 2017. The Governor called Maria the "most devastating storm to hit the island this century."

Damaged homes in the La Perla neighborhood of San Juan on Sept. 21, 2017, the day after Hurricane Maria made landfall in Puerto Rico. The storm knocked out power across the island and many were left without running water or cellphone service.

The powerful winds and rains of Hurricane Maria batter the city of Petit-Bourg on the French Caribbean island of Guadeloupe, Sept. 19, 2017.

A road is flooded in Saint-Pierre, on the French Caribbean island of Martinique, after it was hit by Hurricane Maria, Sept. 19, 2017. Martinique suffered power outages but avoided major damage.

Residents seek shelter inside Roberto Clemente Coliseum in San Juan, Puerto Rico, early on Sept. 20, 2017, as Hurricane Maria passes the island.

Flooded roads are seen in Fajardo after Hurricane Maria hit Puerto Rico on Sept. 20, 2017. 

Damage to homes in San Juan, Puerto Rico, after Hurricane Maria battered the island, Sept. 20, 2017.

Damage in the Miramar neighborhood of San Juan, Puerto Rico, is seen as Hurricane Maria slammed the island on Sept. 20, 2017.

A watches the storm through a window in San Juan, Puerto Rico, on Sept. 20, 2017, during the passage of Hurricane Maria. 

Partially destroyed houses are seen on a flooded road in Fajardo, Puerto Rico, after Hurricane Maria made landfall on Sept. 20, 2017. 

A flooded road is seen after Hurricane Maria hit Puerto Rico, September 20, 2017.

A flooded road is seen after Hurricane Maria hit Puerto Rico, Sept. 20, 2017.

Damaged buildings and power lines in Grand Case, on the French side of the Caribbean island of St. Martin, after Hurricane Maria and Hurricane Irma hit the island. 

People clear debris in Saint-Pierre, on the French Caribbean island of Martinique, after it was hit by Hurricane Maria on Sept. 19, 2017. 

Rescue team members Candida Lozada, left, and Stephanie Rivera embrace as they wait to assist in the aftermath of Hurricane Maria in Humacao, Puerto Rico, Sept. 20, 2017.

Damage is seen to homes in Guayama, Puerto Rico, after the area was hit by Hurricane Maria, Sept. 20, 2017.

Destruction caused by Hurricane Maria is seen in San Juan, Puerto Rico, on Sept. 20, 2017. 

Hurricane Maria caused severe damage on the island of Dominica on Sept. 19, 2017, a day before it hit Puerto Rico.

A search and rescue crew member removes a tree branch from a flooded road as Hurricane Maria hits Fajardo, Puerto Rico, Sept. 20, 2017.

Rain and wind blow trees sideways in a parking lot at Roberto Clemente Coliseum in San Juan, Puerto Rico, on Sept. 20, 2017, during Hurricane Maria. 

A man photographs high waves before the arrival of the Hurricane Maria in Guayama, Puerto Rico, Sept. 19, 2017.