Some Los Angeles County residents are facing dangerous conditions today as polluted air and unsafe water pose threats in several areas.

At least five people were killed and officials expect the death toll to rise as fast-moving, mostly uncontained fires continue to burn across Los Angeles County.

The fires are the most destructive in LA history. As of Wednesday, more than 1,000 buildings had burned and over 130,000 people were under evacuation orders or warnings. More than 200,000 houses and buildings are without power.

Here is the state of affairs:

The major fires: The Palisade fire which is scorching the coastal area between Malibu and Santa Monica, has grown to more than 17,200 acres without containment. The other massive fire moving quickly Eaton Fireovertakes homes throughout Altadena, is 10,600 acres and is 0% contained. The Hurst fire is at least 855 acres and 10% contained, while the Lidia Fire is 348 acres and is 40% embanked. The latest thing to come out is this Fire at sunset in the Hollywood Hills, where evacuation orders have been issued, and is burning 60 acres without containment. The Woodley Fire is now 100% contained after 30 acres burned.

Why the fires spread so quickly: Extreme fire weather sparked fires across Southern California as high winds and low humidity exacerbated conditions. The Wind and fast-moving embers were the biggest factors in causing the fire to spread so quickly, according to Pasadena Fire Chief Chad Augustin. Although the winds died down on Wednesday, they still made it difficult for firefighters. The cause of the Eaton fire is “unknown and remains under investigation,” LA Country Fire Chief Anthony Marrone said. Wildfires are fueled by a number of factors, but scientists say global warming is driving more intense and severe fires.

Fire forecast: Critical fire weather is expected to continue through Friday in portions of Los Angeles and Ventura counties. While much of Southern California is expected to see a brief weakening in wind gusts this morning, the National Weather Service warned that winds are expected to increase throughout the day. Warnings continue to apply to over 10 million people.

Costliest forest fire in history: The According to climate scientist Daniel Swain, the Palisades forest fire alone may be the costliest in history. It is also the most devastating fire in the state’s history, occurring in January.

Specific answer: Firefighters are risking their lives battling the fast-spreading wildfires, with some staff working 36-hour and 48-hour shifts. More than 7,500 fire and rescue workers were mobilized. Nevada is also sending resources from multiple fire departments to Southern California to help with the firefight, and the California National Guard has deployed troops.

Water problems: The City of Pasadena has issued an urgent warning about unsafe drinking water in areas affected by recent evacuations due to the Eaton Fire. According to the city, Pasadena’s water and power systems may be impacted by “debris and increased turbidity.” Residents are advised to rely solely on bottled water for all consumption, including drinking, food preparation, brushing teeth and pet care.

Air quality: The excessive smoke and ash has caused air quality to fall to “hazardous” levels in parts of the region, and air quality warnings are in effect in many areas, including downtown Los Angeles. Altadena has a current air quality index of 426, surpassing the worst air quality observed in the last two days in New Delhi, a city notorious for air pollution.

Learning disrupted: All schools in the Los Angeles Unified School District remain closed today. The district will announce a decision by 4 p.m. PT on whether schools will be open Friday, while all Pasadena schools will remain closed for the rest of the week. Two schools in the Palisades were burned to the ground.