Scottsboro Fire Chief Gene Necklaus said all eight people who were known to be missing have been confirmed dead, and "that number could go up, because we don't know how many were on boats" that sank.
The fire began just after midnight at Jackson County Park Marina and quickly consumed the dock as people were sleeping. The wooden dock at at least 35 vessels went up in flames and an aluminum roof that covered many of the boats melted and collapsed, cutting off escape routes and raining debris over the area as boaters leaped into the river.
"It was scary. The worst thing for me is you could hear people screaming for help, and there was nothing we could do. Nobody could do anything to get to them," said Julie Jackson, who lives with her husband and son in a houseboat on another dock that did not burn at the marina.
At least seven people were sent to hospitals suffering from exposure to the flames or the frigid water.
Necklaus said some of the burning boats sank at the dock and others floated away before going under. He said divers need to locate each one and search them individually before they can be sure there were no other victims.
"We woke up hearing screams and popping noises," Mandy Durham, who was with her boyfriend in a nearby boat, told The Associated Press. "When we woke up, we could see red through the window."
"Within 15 to 20 minutes, the whole dock was in flames," she added. "All these boats have propane tanks and gas tanks, and that's a lot of fire."
The blaze destroyed the B dock, about 50 yards (46 meters) from the A dock where the boat of Durham's boyfriend was moored.
"There were numerous people rescued from the water who had escaped by going into the water," Jackson County Chief Sheriff's Deputy Rocky Harnen told The Associated Press shortly after dawn. "We're trying to get divers down here to search for possible victims."
People were jumping onto a boat at the end of the dock because fire had consumed the middle portion and that was their only escape. But then the flames spread to that boat, leaving water as their only way out, Durham said.
"Water was the only place they had to go," Durham said. "Its just extremely sad. It's horrible."
Georgia resident Michael Watson said his aunt lived with her husband and five children on one of the boats that burned. He said his aunt was confirmed among the dead and authorities are still looking for the other six family members. Officials have not released the names of any of those killed or missing.
Reaching the victims proved challenging for rescue crews.
"The damage from the dock has fallen on top of the boats, and some of the boats have drifted off," Harnen said.
Hours after sunrise, smoke was still rising from the remains of a wooden dock, and pieces of metal that once formed the roof were partially submerged. Police and fire boats with flashing lights were positioned near the charred remains, and a yellow floating boom was being deployed around the marina to contain spilled fuel.
Most of the boats that were destroyed had people living on them permanently, but some mainly spent weekends on them, Durham said. The park includes a boat ramp, a dock and a restaurant, and offers boat rentals, according to Jackson County's government website.
"Everybody is just hoping to find the ones they knew on that dock. There were families there. It's devastating," Durham said.