Mobile Fire-Rescue personnel were battling a 2-alarm structure fire on the Mobile River Wednesday afternoon, with several “potential hazards” on board the oil rig-like structure.

According to a Facebook post from Mobile Fire-Rescue, multiple units responded to the fire at 400 Dunlap Drive.

Fire units arriving at the scene discovered heavy smoke and flames present aboard the structure.

“The rig contains diesel, hydraulic fluid and oil with other potential hazards on board,” according to the post. “Crews are working in tandem to mitigate the incident as quickly as possible. This is a developing scene.”

At least 15 area fire companies had units on the scene.

Mobile Fire-Rescue Chief Jeremy Lami told WKRG the fire began around 1:45 p.m. Workers were cutting up an old semi-submersible platform and a cut sparked a fire, igniting old fuel and oil on the platform.

No injuries have been reported.

According to www.firefighterinsider.com, a two-alarm fire, in addition to requiring more units than a one-alarm, requires two special pieces of equipment — a support vehicle and a hazardous materials vehicle, although requirements can vary by department.

The alarm number does not directly relate to the size of the building or fire, but rather reflects how many firefighters and how much equipment is needed to fight the fire.