A team of New York electricity-transmission workers and a pair of drone operators arrived in San Juan Friday to help the reeling government of Puerto Rico begin to measure the damage to the U.S. territory’s power grid.

The entire island remained without electricity into the weekend, days after Hurricane Maria thrashed its fragile and neglected network of plants, lines and poles.

The Puerto Rico Electric Power Authority, known as PREPA, is unable to complete the task of restoring power on its own: It is bankrupt, just like the Puerto Rican government. The utility would not begin regular operations until Monday to “avoid jeopardizing the safety of its employees,” according to its executive director, Ricardo Ramos.

Related: Puerto Rico’s Failing Guajataca Dam Endangers Thousands

In addition, when Maria hit, PREPA was in the midst of restoring power to the last of 1 million households that went black during Hurricane Irma only weeks earlier.

This time, there’s no telling how long the power outages will last.

Image: Hurricane Maria Bears Down On Puerto Rico

Police cars make their way down darkened streets during a blackout in San Juan on Sept. 20.