Miami-Dade County rescue teams are still battling fires, water and shifting materials at the at the Surfside collapse site almost 30 hours after the building crumbled to pieces in the middle of the night, Florida State Fire Marshal Jimmy Patronis told CNN’s Sanjay Gupta Friday morning.

“You get a lot of lithium-ion batteries and other combustible materials that eventually they will catch to a point where they will ignite,” he said. 

Crews are using search dogs to comb through the rubble “and of course listening for anything that could be a clanging, but as you’re pumping water out, you’re also shifting materials that creates a ripple effect and you’re competing with all the noise of the equipment,” said Patronis. 

“They’re doing the best they can with what they’ve got, [its] a tremendous risk,” Patronis added. 

“You’re adding water to the building to control the fire while men and women are saving lives, and that water adds a tremendous amount of weight. It then challenges the integrity of what’s still standing there, and then that delicate balance of saving lives while risking lives,” Patronis said. 

Patronis said added “they’re being innovative.” Crews are “looking at the license plates of the cars that are in the parking garage to try to do more cross-referencing and matching to verify that people are in or out of the building as you assemble this manifest, [and] as you talk to the loved ones in the unification center,” said Patronis. 

“We had every department in this region in response, but the skill set that these men and women have are unique,” said Patronis of Miami-Dade Fire Rescue teams. “They are…built to go from building to building after hurricane disaster, manmade or natural, they’re used to digging through debris to find lives.”

Rescue teams from Orlando and Naples are expected to arrive later today to supplement the rescue efforts.