Power has been restored to most of Puerto Rico after a transformer fire at an electric companys substation on Thursday left hundreds of thousands without electricity. 

There are currently still 19,000 people on the island without power, but the number is a significant decrease from the 900,000 who were affected at the height of the outage, according to a press release by Luma, the company that took over Puerto Ricos power transmissions at the beginning of June.

The companys website says it expects all the power to be restored by 6 p.m. eastern standard time Friday.

Last nights events speak for themselves. We were able to move quickly with our teams. We managed a substantial amount of work safely, so I can say were ready. We have a great team at LUMA. Right now, we have about 1,200 employees on the street working around all of Puerto Rico, Wayne Stensby, president and CEO of Luma, said Friday.

Authorities will be investigating the cause of the fire as the company has not determined why the fire began.

Along with the fire, Luma experienced a cyberattack that inhibited the ability of customers to get in contact with the company during the outage. 

Luma signed a 15-year contract with the government to take control of Puerto Ricos power grid and the government asked its citizens to be patient as the company just took over the system.

The infrastructure for the grid is still devastated by Hurricane Maria that hit the island in 2017.