LAKE COUNTY, Fla. — Many of the brush fires across Central Florida recently have become muck fires.
Muck fires are fires that burn underground and lead to smoky, hot, dangerous conditions for residents in the area.
"It's very difficult. Sometimes they can last for a month or more," said David Anken, with the Florida Forest Service. "It's kind of like a clay oven, just baking deeper and deeper."
Lake, Volusia, Orange and other Central Florida counties have recently dealt with a series of brush and muck fires due to the extreme dry conditions.
"The muck's just a buildup of grasses over the years. When everything dies off in the winter and it comes back in the spring, you've got that thatch. Over years, it builds up and it starts compacting itself down and it forms this dense, muck material," Anken said.
State Road 44 was shut down between County Road 44A and Royal Trails Road because of what began as an almost 800-acre fire, officials said. That road has since reopened.
School buses didn't pick up Lake County students Friday morning along a closed section of State Road 44 in the Royal Trails and Pine Lakes area because of smoke from a nearby brush fire.
The road was also shut down Monday, Tuesday, Wednesday and Thursday mornings. But the road reopened later on each of those days.
[ Photos: Large brush fire in Eustis ]
The change affected students from Umatilla Elementary, Umatilla Middle, Umatilla High, Eustis High, Eustis Middle and Seminole Springs Elementary schools.
The absences of students who were unable to attend school because of transportation issues will be excused, and any tests that were missed will be rescheduled.
[ Photos: Severe drought affecting Central Florida lakes and rivers ]
Lake County Schools will continue to monitor the situation and will update via callout and postings on the district's website and social media pages if there are any changes.
Click here to read information from the Centers for Disease Control and Prevention on how to protect yourself from wildfire smoke.
Most of Central Florida is under a burn ban, according to the Florida Forest Service. The agency also released an interactive map of the current muck fires and wildfires in the state.
Channel 9's Lauren Seabrook is following this story. She'll have more on Eyewitness News at 4 p.m.
[ Interactive map: Current drought conditions in Central Florida ]