SAN JUAN, Puerto Rico – An island-wide blackout hit Puerto Rico on Wednesday after an excavator accidentally downed a transmission line, officials said, as the U.S. territory struggles to repair an increasingly unstable power grid nearly seven months after Hurricane Maria.Officials said it could take 24 to 36 hours to fully restore power to more than 1.4 million customers as outrage grew across the island about the state of Puerto Rico’s Electric Power Authority. It was the second major outage in less than a week, with the previous one affecting some 840,000 customers.“This is too much,” said Luis Oscar Rivera, a computer technician who just got normal power back at his house less than two months ago. “It’s like the first day of Maria all over again.”Authorities said the same contractor was involved in the two latest big power failures and had been fired. The outage last Thursday was set off when a tree limb fell on a power line as the contractor cleared land in central Puerto Rico and a backup line failed. On Wednesday, an excavator used by the contractor hit a transmission line near the south coast.Several large power outages have hit Puerto Rico in recent months, but Wednesday was the first time since the hurricane struck Sept. 20 that the U.S. territory has experienced a full island-wide blackout.The outage snarled traffic across the island, interrupted classes and work, and forced dozens of businesses to temporarily close, including the largest mall and popular tourist attractions like a 16th century fort in the historic part of Puerto Rico’s capital. Long lines formed stations across the island, while authorities offered assurances that there was enough gasoline available.Backup generators roared to life at the island’s largest public hospital and at its main international airport, where officials reported no cancellations or delays. Meanwhile, the power company said its own customer service centre was out of service and asked people to go online or use the phone.Officials said restoring power to hospitals, airports, banking centres and water pumping systems was their priority. Following that would be businesses and then homes.By late in the afternoon, power had returned to several hospitals and at least five of the island’s 78 municipalities.Carmen Yulin Cruz, mayor of the capital of San Juan, said the outage would not interrupt the last of a two-game series between the Cleveland Indians and Minnesota Twins, which is being played on the island. She said all emergency systems at Hiram Bithorn stadium are functioning and that tower lights and additional security will be placed at the stadium’s parking lot.Justo Gonzalez, the power company’s executive sub-director, told reporters that workers were removing a collapsed tower Wednesday during unrelated power restoration efforts near the south coast and an excavator hit the transmission line.“We are working in areas that are quite crowded with high voltage lines,” he said.Fredyson Martinez, vice-president of a union that represents power company workers in Puerto Rico, told The Associated Press that he was concerned about the two back-to-back incidents.“That is not normal,” he said.Government officials said a company hired by Cobra Energy known as Dgrimm was involved in both incidents that led to the power outages. Dgrimm had been asked to change its security protocols after the first incident, and it has since been terminated, said William Rios, power generation director.“This is unacceptable for us,” he said, adding that government attorneys were meeting with officials at Cobra Energy, a Mammoth Energy subsidiary.Angel Figueroa, president of the power workers’ union, told reporters that workers were investigating why a backup breaker at a main power station in the island’s southern region did not function when the outage occurred, causing the entire electrical grid to shut down to protect itself. He noted it was the same problem that caused a 2016 power outage that affected the entire island.Geraldo Quinones, a power company spokesman, said in a phone interview that crews are investigating why the breaker failed.Rivera said he worries that such serious power outages are still occurring as the new Atlantic hurricane season, which starts on June 1, approaches.“If there’s a slight storm, we’re going to be worse off than we are right now,” he said.Federal officials who testified before Congress last week said they expect to have a plan by June on how to strengthen and stabilize the island’s power grid, noting that up to 75 per cent of distribution lines were damaged by high winds and flooding. Meanwhile, the U.S. Army Corps of Engineers, which is overseeing the federal power restoration efforts, said they hope to have the entire island fully energized by May. Some 40,000 power customers still remain without normal electrical service as a result of the hurricane.The new blackout occurred as Puerto Rico legislators debate a bill that would privatize the island’s power company, which is $14 billion in debt and relies on infrastructure nearly three times older than the industry average.