All three were taken to the Fulton County jail after being charged following interrogation by investigators Friday afternoon.
“We believe they were together when the fire was set and Eleby is the one who set the fire,” Florence said.
Florence said officials do not believe anyone else was involved in setting the fire, which quickly engulfed construction materials stored beneath the interstate at Piedmont Road. Allen said the charges could be “upgraded” as investigators develop more evidence.
Florence declined to say how the fire was started. However, he said the suspects used “available materials” at the site. The Georgia's Department of Transportation is working to determine the extent of the damage caused by the fire.
GDOT began its assessment of the damage Thursday before the fire was even extinguished, Georgia Department of Transportation Commissioner Russell McMurray said Friday.
Related: Repairs expected to take months after large fire leads to Atlanta interstate collapse
Demolition crews are already working to remove tons of crushed concrete and look for clues as to how coils of non-combustible high-density plastic pipe, which GDOT stored underneath the bridge, caught fire.
"So the storage area under the bridge was storing normal highway construction materials. The PVC material has been there for some time, probably since 2006 or 7," McMurry said.
The massive blaze started at about 6:15 p.m. Thursday beneath I-85 northbound.
Both northbound and southbound lanes of I-85, as well as several roads in northeast Atlanta, were closed for hours Thursday and into Friday. Interstate 85 will remain closed as crews rebuild the bridge on both sides.