SAO PAULO (AP) — More than 1.3 million Sao Paulo residents remained without electricity late Thursday after strong winds caused trees to fall onto the Brazilian metropolis’ grid the day before. Authorities said almost 400 flights were canceled.

Utility Enel said in a statement it had returned services to 1.2 million of its 2.2 million clients in and around Sao Paulo, but that another 300,000 lost electricity throughout Thursday.

Enel claims the issue was caused by winds of about 100 kilometers per hour (62 miles) started hitting the metropolis since Wednesday. It did not provide a deadline to finish all the fixes.

“In some parts (of the city) work is taking longer because it includes the complete reconstruction of the grid,” Enel said. The company added it is offering generators to hospitals and clients who depend on essential electric devices.

Sao Paulo city hall said 231 trees have fallen due to what it calls effects of an extratropical cyclone formed in the south of Brazil. Aviation authorities say most of the canceled flights were at the local Congonhas airport, but added that Guarulhos International Airport, outside the city, was also affected.

Mayor Ricardo Nunes, whose administration is responsible for trimming the trees that were pushed against the grid, told journalists Wednesday night he had told the company that it was not putting all of its efforts to fix the problems.

“Every time something happens, we are left behind without electricity,” said Nunes, who called the Italian utility company “irresponsible.” The grid’s status on Wednesday was even worse, with more than 2 million Sao Paulo residents without electricity.

On Thursday, several cars with the Enel logo were filmed in the company’s parking lot in downtown Sao Paulo, which further enraged residents and authorities.

Water utility Sabesp said in a statement on Thursday that the lack of electricity is already affecting their services too, as pumps are not working adequately.

Many paulistanos — as Sao Paulo residents are known — went to shopping malls and coffee shops to be able to work. Psychologist Thaisa Fernandes, 45, had no electricity at her home in the upscale region of Vila Madalena and chose to speak to her online patients at a snack bar.

“They sent several estimates as to when services would be returned, all failed. It is the third time this year alone. Neither the company nor these local authorities are to be trusted,” Fernandes said.

Many passengers still queued at Congonhas airport as of Thursday evening without any clarity on whether their flights would take off, which is already affecting other airports in Brazil, passengers and airline staffers say.