JUDY WOODRUFF: Officials in Arizona say a wildfire that killed 19 firefighters yesterday has now destroyed more than 8,300 acres and engulfed 13 square miles. It was the biggest loss of firefighters in a wildfire since 1933. They ranged in age from 21 to 43 years old.

The fire is still burning unchecked tonight, leaving crews to carry on their work with heavy hearts for their fallen colleagues.

Views from above showed orange flames consuming the Arizona skyline, as more than 400 firefighters tried to contain the Yarnell Hill fire, which has more than quadrupled in size since yesterday. Sparked by a lightning strike on Friday, it's located 85 miles northwest of Phoenix and about an hour southwest of Prescott, which is home to the Granite Mountain Hot Shot firefighting crew seen here in a training video from 2012.

The city's fire department confirmed 19 of the elite team's 20 members died yesterday while battling the blaze. The surviving member was moving equipment at a different location. The bodies of the team were retrieved from the site today, a day after fire chief Dan Fraijo mourned those lost.

DAN FRAIJO, fire chief, Prescott, Ariz.: Fire departments are like families. And so the entire fire department, the entire area, the entire state is being devastated by the magnitude of this incident. These are the guys that will go out there with 40, 50 pounds of equipment and walk five miles. They will sleep out there as they try to develop fire lines and put protection between homes, natural resources and still try to remain safe. These are quality people.

JUDY WOODRUFF: Officials said in battling the flames the firefighters were forced to wrap themselves in tent-like shelters made of fire-resistant material like these seen in the training video, a last-ditch method used in hopes that the fire would burn over them; 19 roses were among the items left at a makeshift memorial outside Fire Station 7 in Prescott, where the Granite Mountain Hot Shot team is based.

This morning, Arizona State Forestry Division spokesman Mike Reichling said weather conditions continue to be erratic.

MIKE REICHLING, Arizona State Forestry Division: This weather has really caused havoc on this fire with the types of fuels. As we said yesterday, the area has not been touched by fire for over 40 years. We have been in over a 10-year drought throughout the state.

JUDY WOODRUFF: Hundreds have been forced to leave their homes. One man described escaping with his wife as the fire moved in on their property.

CHUCK OVERMYER, survivor: We had to drive through the flames to get out of our gate. It was already that bad.

Within two minutes -- I would say if we waited another two or three minutes, we wouldn't have got out of there. It was that fast coming in.

JUDY WOODRUFF: An investigation is under way into the deaths of the firefighter.

President Obama issued a statement, calling the firefighters heroes and said his administration would help investigate how the deaths happened.