The deadly Yarnell Arizona area wildfire that killed 19 firefighters has officially been designated as half contained. Over 600 firefighters are now on the front line of the fire that has burned over 13 square miles.

And as their brothers-in-arms are paying tribute to the fallen firefighters, local officials have stated that they believe it’s possible residents who refused to listen to evacuation orders died in the flames. They will not be able to get an official death toll until the flames are extinguished.

The fire has been extremely unpredictable in motion which has made conditions for the firefighters unusually treacherous.

“The fire moved approximately four miles in just 20 minutes,” Sheriff’s Department Chief Deputy John Russell told the BBC.

Fire officials have been taking extra precautions around the region for Fourth of July fireworks displays to make sure no additional wildfires are sparked by fireworks.