SACRAMENTO (CBS13) – More than 500 SMUD customers were still without power two days after a fire at a downtown substation.

New documents show the substation that caught fire needed improvements, and SMUD was planning on change before the explosion.

READ MORE: Man Arrested In South Sacramento After ShotSpotter Activation

SMUD says repair work continued around the clock to get power back in days instead of weeks. They’re planning on Friday morning for full power restoration.

Work continued Thursday evening to restore power to the substation that exploded Tuesday, creating a smoke cloud above downtown Sacramento.

The fire damaged equipment and created days of darkness for businesses and restaurants in a six-block radius around the substation.

“The smoke just poured out,” one neighbor said. “There were fire personnel everywhere.”

A public 260-page project assessment from SMUD says the substation was “near the end of useful life” and “requires replacement, upgrades and additional space.”

The report is from 2015.

The document also shows, in the same year, SMUD planned to make repairs to the site, including installing new equipment on a lot on the north side of the substation and to take parts of the older facility offline.

They also looked into a new building which would keep electrical equipment.

READ MORE: Verizon Delays 5G Rollout Again Amid Safety Concerns At Airports

In 2017, the City of Sacramento gave permission for the expansion and repair, but city leaders told CBS13 that is as far as the city was involved in the project.

In 2020, another change was proposed: SMUD planned to “decommission” the substation altogether and remove the equipment from the historic building.

That project was set to start next year.

CBS13 asked leaders with SMUD about the report. They confirm they were looking for a new larger substation to accommodate the growing grid, but also say the current substation was never a safety hazard.

In a statement, leaders say “useful life is fluid and can vary greatly dependent upon the care and maintenance of the site. It does not mean the system was unsafe.”

It’s still not clear what started the fire.

SMUD also says inspectors assess equipment every two months. Station A was last inspected in October, and another inspection was set to happen later on this month.

Station A is planned to be transferred to a new substation, substation “G” which is just across from the facility in October of 2022.

MORE NEWS: Woman Charged In 'Largest EDD Fraud Scheme' In Sacramento County

They expect the full move by May 2023. The fire impacted outdoor, external equipment only and not the historic building, which is mostly empty.