May 31 (UPI) — St. Thomas and St. John were hit with blackouts over the weekend, as the U.S. Virgin Islands combats its energy insecurity issues.

The Virgin Islands Water and Power Authority said in a statement that the power issues stem from operational instability at a power plant. It said the outage was caused by a mechanical fault, and personnel were working to bring every customer back online.

The first blackout was reported Saturday followed by one on Sunday.

As of Sunday night, nearly 60% of St. Thomas was without power while St. John appeared to be back online, according to poweroutage.us, which said Virgin IIslands Water and Power Authority ranks second for total power outages and second for percentage of customers affected among all utilities nationwide.

Those without power Sunday night accounted for about 22% of the U.S. Virgin Islands’ 54,667 customers, it said.

The utility said Sunday evening that personnel were working to maintain services “for as many customers as possible,” warning customers to expect “two-hour outages when affected.”

Virgin Islands Gov. Albert Bryan Jr. announced in July 2024 that the Biden administration had approved a $100 million grant for the Virgin Islands Water and Power Authority to acquire fuel storage infrastructure to aid the region’s energy supplies.

According to the U.S. Energy Information Administration, nearly all energy consumed in the U.S. Virgin Islands is provided by imported petroleum products, 60% of which is propane.

The residential sector accounts for about 43% of the region’s energy consumption, it said.