(CNN) On the same day Puerto Rico's governor celebrated power generation on the island reaching 50% of capacity, the lights went out in the San Juan metro area.

The source of Wednesday's outage was the same main north-south transmission line that failed last Thursday, leaving swaths of the capital without power for hours, officials said.

But the latest interruption appeared to cover a larger area, including Bayamon,GuaynaboSan Juan, Carolina and other municipalities, said Justo González Torres, director of power generation for the Puerto Rico Electric Power Authority , known as PREPA.

A down economy and high migration away from the island to mainland America means lots of vacant buildings on the island. The governor announced Puerto Rico would seek a form of bankruptcy protection to restructure its $70 billion-plus debt in May 2017, the largest municipal restructuring in US history.

A down economy and high migration away from the island to mainland America means lots of vacant buildings on the island. The governor announced Puerto Rico would seek a form of bankruptcy protection to restructure its $70 billion-plus debt in May 2017, the largest municipal restructuring in US history.

Puerto Rican identity has played a prominent role in popular culture and entertainment. Hip-hop and breakdancing grew out of a multicultural New York landscape that included African-American and Puerto Rican youths. Here, a production of "West Side Story" features the fleet-footed Puerto Rican Sharks gang.

Puerto Rican identity has played a prominent role in popular culture and entertainment. Hip-hop and breakdancing grew out of a multicultural New York landscape that included African-American and Puerto Rican youths. Here, a production of "West Side Story" features the fleet-footed Puerto Rican Sharks gang.

The Zika epidemic presented a threat to the health of Puerto Ricans as well as a blow to the island's tourism industry. While the crisis was declared over in June 2017, more than 35,000 cases were reported there in 2016, and a public health emergency was enacted. Here, Michelle Flandez holds her son Inti Perez, diagnosed with microcephaly linked to the mosquito-borne virus.

Tourism is big business throughout the island and pulls in about $4 billion annually. The Castillo San Cristóbal in San Juan is a top attraction. It's one of the largest fortresses built in the Americas, constructed to protect the island from military attack.

A woman leaves a voting station after casting her ballot in the June 2008 Democratic presidential primary between Hillary Clinton and Barack Obama in San Juan. Puerto Ricans can vote in US primaries but not in presidential elections.

A woman leaves a voting station after casting her ballot in the June 2008 Democratic presidential primary between Hillary Clinton and Barack Obama in San Juan. Puerto Ricans can vote in US primaries but not in presidential elections.

Puerto Ricans last voted on the question of statehood in 2017 . In the nonbinding referendum, 97% of the votes favored statehood, but voter participation was just 23% after opposition parties called for a boycott. Congress, the only body that can approve new states, will ultimately decide whether the status of the US commonwealth changes.

Puerto Ricans have been US citizens since 1917, and the island has been a US commonwealth since 1952. Puerto Rico wrote its own constitution, which was approved by Congress and signed by President Harry S. Truman.

Puerto Ricans have been US citizens since 1917, and the island has been a US commonwealth since 1952. Puerto Rico wrote its own constitution, which was approved by Congress and signed by President Harry S. Truman.

People fill pails with water at the Christopher Columbus Fountain in Aguadilla, Puerto Rico, in 1920. Here, Columbus is said to have stepped on the shore and taken his first American drink.

People fill pails with water at the Christopher Columbus Fountain in Aguadilla, Puerto Rico, in 1920. Here, Columbus is said to have stepped on the shore and taken his first American drink.

Puerto Rico's first governor, appointed in 1509, was Spanish explorer Juan Ponce de León. He named a city on the island Puerto Rico, or "rich port," which later became the name by which the entire island was identified.

Puerto Rico's first governor, appointed in 1509, was Spanish explorer Juan Ponce de León. He named a city on the island Puerto Rico, or "rich port," which later became the name by which the entire island was identified.

The cause of the outage was an unspecified "technical failure," he said.

González said the authority hoped to restore power in the coming hours.

The outage came hours after Gov. Ricardo Rosselló tweeted that the power authority had completed its stated goal of 50% generation for Wednesday.

San Juan Mayor Carmen Yulín Cruz promptly replied via Twitter, telling the governor the percentage of power generation "has just changed" and the municipal medical center and other buildings were in the dark.

Shortly after noon, PREPA tweeted that power had been restored to the medical center and several other locations.

With the latest outage, power generation plummeted from 50% to 22% of capacity, PREPA said on Twitter Wednesday afternoon. It later rose to 29%, the utility company said, noting that the goal is to reach 80% by the end of the month.

González said capacity had reached 49.9% on Tuesday, and 50% for part of Wednesday morning. Much of Puerto Rico has been without power since Hurricane Maria smashed the island on September 20.

'You'd laugh if only you weren't crying'

"What has happened today shows that what the government is saying has nothing to do with what's really happening in the country, said Christian Ibarra, 30, a writer for an ad agency in San Juan.

"It's a reflection that's laid bare years of improvisation. The same people always lose. This has caused an economic and humanitarian collapse that would be unacceptable in any other state in the US."

Ibarra added, "What should amaze us is that things are getting worse and being done worse each time. It's about basic services in the 21st century."

A post on the Facebook page of the Plaza Las Americas mall seemed to capture the sentiment of many Puerto Ricans frustrated with the island's recovery.

"You'd laugh if only you weren't crying," it said, adding that the mall had to close for the day.