(Reuters) - Puerto Rico, a U.S. territory of 3.4 million people, struggled through a 10th day with virtually no electricity, patchy communications and shortages of fuel, clean water and other essentials in the wake of Hurricane Maria, the most powerful storm to hit the island in nearly 90 years.

A man stands inside of a destroyed supermarket by Hurricane Maria in Salinas, Puerto Rico, September 29, 2017 REUTERS/Alvin Baez

The storm struck on Sept. 20 with lethal, roof-ripping force and torrential rains that caused widespread flooding and heavily damaged homes, roads and other infrastructure.

These are the resources deployed by the United States to Puerto Rico as of Saturday:

MILITARY RESPONSE

- There are about 4,500 U.S. troops on the ground in Puerto Rico, including active duty and national guard. An additional 1,400 National Guard members are expected to arrive in Puerto Rico in four days.

- Forty-three officials from the Federal Emergency Management Agency, teams of U.S. Army Corps of Engineers and more than 1,600 National Guard members had sheltered in place during the storm.

- The U.S. military has the USS Kearsarge and Oak Hill, amphibious assault ships, assisting in relief efforts. The USS Wasp, which has completed relief efforts off the coast of Dominica, will soon be joining them.

- The USNS Comfort, a hospital ship, is en route to Puerto Rico and expected to arrive on Oct. 4. The Comfort is equipped to carry up to 1,000 hospital beds, 12 operating rooms and one of America’s largest trauma units.

- Fifty-two tilt/rotary-wing aircraft are taking part in efforts, according to the Pentagon.

- A Defense Logistics Agency shipment of 100 trucks with diesel and fuel will arrive in next few days.

- The Defense Logistics Agency is preparing to distribute potentially 160 million meals in 30 days.

- By Friday, 15,000 gallons of propane were expected to arrive in Puerto Rico.

- On Thursday, a C-5C aircraft landed with a generator to help radar approach operations, the Pentagon said.

POWER AND WATER

- There are 4,000 people working to restore electricity and private U.S. companies will be bringing in 1,000 additional workers this weekend, the Puerto Rico Electric Power Authority (PREPA) said.

- Only 5 percent of the electricity grid had been restored by Saturday, FEMA officials said.

- About 50 percent of people on the island had access to water on Friday, according to FEMA.

- The U.S. Army Corps of Engineers has completed a damage assessment at the Guajataca dam and repairs are scheduled to begin on Sunday and Monday.

The dam’s spillway continues to erode following 2 to 3 inches (5 to 7.5 cm) of rain over the past day, with another 2 to 4 inches each day over the next two days expected, the military said, citing the National Oceanic and Atmospheric Administration.

INFRASTRUCTURE

- The Pentagon said eight airports are open and one is still closed.

- Five of the six FEMA-priority sea ports are open or open with restrictions, according the U.S. military.

- A Pentagon release, citing FEMA, said 851 of 1100 retail gas stations had re-opened by Saturday morning.

- About 90 percent of cell phone sites on the island remain out of commission, according to the U.S. Federal Communications Commission.

- About 33 percent of the overall telecommunications network had been restored as of Saturday afternoon, FEMA said.

- According to a Pentagon update, which cites FEMA, 59 of the island’s 69 hospitals were fully or partially open and five were closed. Five other hospitals not yet assessed by the military do not provide emergency care.