After Hurricane Maria, Puerto Rico was in the dark for

Hurricane Maria slammed into Puerto Rico in the early hours of Sept. 20, bringing 155 mph winds that knocked the majority of the 3,500-square-mile island into one of its longest widespread power outages since Hurricane Jeanne made landfall in 2004.

More than 60 people have died since the storm hit. However, reports suggest the actual death toll might be more than 1,000.

Officials warned the storm’s destructive blow to Puerto Rico’s aging electrical infrastructure could take months to repair.

Two months after Maria made landfall on Sept. 20, the majority of the island’s 3.4 million people were still without power. On Nov. 28, the Department of Energy reported, for the first time, that more than half of normal peak load electricity was restored. Residents have relied on portable generators as workers across the island try to repair the damaged electrical grid.

In the days after Maria, many residents struggled to access gasoline, food, water, money and a cellphone signal to contact family members.

Others, especially those without electricity, have been cut off from the outside world.

In the island’s mountainous regions, massive landslides prevented local and federal assistance from reaching residents for more than a week.

In the town of Dorado, residents waited for water outside a hazardous-waste site. The EPA-designated Superfund site had groundwater contamination levels below legal thresholds, which prompted concerns of disease and infection.

The number of people regaining power has steadily increased since Maria made landfall, though incidents of tripped lines have caused fluctuations.

[Related: Trapped in the mountains, Puerto Ricans don’t see help, or a way out]

Outside the island, the outage also could have consequences on the mainland United States.

The U.S. Food and Drug Administration warned the outage could cause drug shortages. Puerto Rico manufactures nearly 10 percent of medicine used by Americans, including numerous medical devices.

When a blackout occurs in the United States, workers from across the country often converge, usually by road, to the site.

The situation is different in Puerto Rico.

[Related: Trump’s Puerto Rico video tells positive story but leaves a lot on cutting-room floor]

Workers and tools are flown to the island. Heavy equipment, such as bucket trucks, transformers and wires, are transported by ships.

When workers and equipment arrive, the next challenge is repairing downed lines among the Puerto Rico Electric Power Authority (PREPA)’s 2,478 miles of transmission lines, clearing debris from roads and providing food and water to residents.

Several U.S. utility companies have sent workers to help PREPA with restoring power.

On Oct. 19, Whitefish Energy announced it signed a $300 million contract with PREPA to repair and reconstruct large portions of the electrical infrastructure. The company, which employed only two people when Maria made landfall, is based in Whitefish, Mont., the hometown of Interior Secretary Ryan Zinke.

The contract, however, drew scrutiny and criticism from Congress. On Oct. 27, the Federal Emergency Management Administration, which controls government reimbursements, said it had "significant concerns" about how Whitefish secured the contract.

The governor of Puerto Rico, Ricardo Rosselló, asked PREPA to cancel the contract two days later.

The downed lines connected to PREPA-owned power plants are decades old.

The island’s electrical grid, which President Trump described to “in terrible shape,” had deteriorated from a lack of maintenance even before the one-two punch of Irma and Maria.

PREPA, one of the largest public utilities in the United States and its territories, has been historically underfunded, its finances in decline since 2013.

A combination of inadequate infrastructure investments, staff departures and a leadership team that made “bad bets” have left PREPA’s system “in a state of crisis,” according to a November 2016 report published by Synapse Energy, a Massachusetts-based energy consulting firm.

“PREPA’s system today appears to be running on fumes,” the authors wrote, adding the company needed “an infusion of capital — monetary, human, and intellectual — to restore a functional utility.”

[Related: Hurricane Maria has dealt a heavy blow to Puerto Rico’s bankrupt utility and fragile electric grid]

Before the hurricanes, PREPA said it required more than $4 billion to overhaul its outdated power plants and reduce its years-long reliance on imported oil.

This has caused the island to have some of the most expensive electricity rates in the United States and its territories.

In July, PREPA filed for bankruptcy with $9 billion in debt, according to the Puerto Rico Fiscal Agency and Financial Advisory Authority.

The millions of dollars in repairs after Maria will add an additional burden to the already struggling company, which could delay power restoration to the rest of Puerto Rico.

PREPA’s debt is only a small chunk of Puerto Rico’s overall public debt, which climbed to more than $72 billion in 2015.

Puerto Rico's unemployment rate is twice the U.S. average, 10.1 percent in August compared with 4.4 percent on average in the United States.

High poverty rates, exacerbated by the recession and mass emigration from the island to the mainland, especially among the educated class, have also contributed to Puerto Rico’s economic turmoil.

By the end of October, more than 20,000 federal workers were sent to Puerto Rico and the U.S. Virgin Islands in response to hurricanes Maria and Irma, according to FEMA.

In January, the U.S. Army Corps of Engineers said Irma and Maria left 6.2 million cubic yards of debris around the island, adding workers have removed nearly a third thus far.

[Related: FEMA removes statistics about drinking water access and electricity in Puerto Rico from website]