ABC News September 26, 2017

Puerto Rico left in the dark after Hurricane Maria, photos show

WATCH: Hurricane-ravaged Puerto Rico facing 'unprecedented disaster'

Hurricane Maria struck Puerto Rico as a Category 4 storm on Sept. 20, battering the U.S. territory and leaving the majority of residents without power.

FEMA search and rescue task forces are continuing to conduct operations on the island. As of Monday, the teams had rescued 557 people and two pets while searching over 2,600 structures in the Caribbean. The U.S. Coast Guard is continuing its search and rescue operations as well and working to restore communications towers in the Caribbean.

Use the slider tool to see the island via satellite before and after Maria:

Puerto Rico Gov. Ricardo Rossello said the island is facing an "unprecedented disaster" in the wake of Maria, which killed at least 16.

Photos taken on Puerto Rico show the devastation and ongoing struggles on the island:

Carlos Garcia Rawlins/Reuters
A doctor checks the eyes of Hilda Colon at a shelter set up at the Pedrin Zorrilla coliseum after the area was hit by Hurricane Maria in San Juan, Puerto Rico, Sept. 25, 2017.

A doctor checks the eyes of Hilda Colon at a shelter set up at the Pedrin Zorrilla coliseum in San Juan after the area was hit by Maria.

Carlos Garcia Rawlins/Reuters
Carlos Cruz wakes up after sleeping in a shelter set up at the Pedrin Zorrilla coliseum after the area was hit by Hurricane Maria in San Juan, Puerto Rico, Sept. 25, 2017.

Carlos Cruz wakes up after sleeping in a shelter set up at the coliseum.

Ricardo Arduengo/AFP/Getty Images
People use their cell phones at night in one of the few places with cell signal in San Juan, Puerto Rico, Sept. 25, 2017, where a 7pm-6am curfew has been imposed following impact of Hurricane Maria on the island.

People use their cellphones at night in one of the few places with cell signal in San Juan, where a 7 p.m. to 6 a.m. curfew has been imposed.

Ricardo Arduengo/AFP/Getty Images
A woman checks her cell phone next to a road at night in one of the few places with cell signal access in San Juan, Puerto Rico, Sept. 25, 2017.

A woman checks her cellphone next to a road at night in San Juan.

Hector Retamal/AFP/Getty Images
Maria prepares food next to her home, destroyed by Hurricane Maria, in Toa Alta, Puerto Rico, Sept. 25, 2017.

Maria prepares food during nightfall next to her home, destroyed by Hurricane Maria, in Toa Alta.

Alvin Baez/Reuters
A man tries to repair a generator in the street after the area was hit by Hurricane Maria in San Juan, Puerto Rico, Sept. 25, 2017.

A man tries to repair a generator in the street in San Juan.