The California department of justice has launched a civil rights investigation into whether Los Angeles county discriminated against the predominantly Black community of west Altadena when responding to last year’s Eaton fire.

The investigation will assess whether the fire response resulted in a “disparate impact” on west Altadena based on race, age or disability.

Residents of the unincorporated community’s more affluent and whiter eastern side received evacuation alerts within an hour after the fire started, while west Altadena residents received alerts some eight hours later, according to the Los Angeles Times. As the flames began to engulf west Altadena around 3am local time, a single fire truck had reached the area to fight it off, while dozens had been deployed to Altadena’s east side.

Those vast disparities have long driven charges that the Los Angeles county failed west Altadena’s residents, thousands of whom remain displaced more than a year later.

“There was, indisputably, a delayed emergency notification and evacuation of west Altadena,” Rob Bonta, the California attorney general, said in a press conference livestreamed on Thursday. “We’re here to ask why.”

The notification delays and lopsided dispersal of firefighting resources appear to have cost west Altadena dearly. All but one of the 19 people who died in the 14,000-acre Eaton fire were residents of west Altadena. Nearly six in 10 Black-owned homes were damaged.

“The investigation we’ve launched is driven by one overarching question: did the Los Angeles county fire department’s delay in notifying and evacuating the historically black west Altadena community during the Eaton fire violate state anti-discrimination and disability rights laws?” Bonta said. “Did unlawful race-, disability- or age-based discrimination in the emergency response result in a delayed evacuation notification that disproportionately impacted west Altadena residents?”

The Los Angeles county fire department did not immediately respond to a request for comment.

Altadena for Accountability, a group of residents affected by the fire, called the investigation “a trailblazing move for civil rights and environmental justice” in a press release.

“No other analysis or report has done what this investigation will do – only the attorney general has the authority and subpoena power to examine whether our civil rights were violated,” Sylvie Andrews, a fire survivor, said in a statement.