Florida wildfires left drivers blocked on roads in Key Largo, causing widespread devastation.

The blaze erupted along the 18-Mile Stretch of US Highway 1 on Tuesday afternoon, March 18, and intensified due to high winds and dry conditions, rapidly expanding to cover approximately 3,600 acres.

US Highway 1 and Card Sound Road, the primary routes connecting the Florida Keys to mainland Miami-Dade County, were closed Tuesday afternoon.

Officials reported that US Highway 1 reopened by the evening, but Card Sound Road remained closed as of Wednesday morning, with no reopening estimate provided by Monroe County officials.

Dramatic footage shows a line of stranded vehicles, with a firefighting helicopter visible against an orange sky filled with smoke.

Bennett Lessmann, a Boca Raton attorney heading to Marathon, said: 'You can't tell where the fire is.'

Another driver, Tom Richards, who was stuck on the road after a doctor's trip with his friends, added: 'They closed the damn road right as we got here.'

Cody Hinkle, who was also trapped in the area, said: 'I thought it was just clouds.'

Although no injuries were reported, authorities stated that the flames had damaged power lines and communication towers.

The Florida Forest Service reported that by Wednesday afternoon, the fire had burned approximately 4,000 acres and was 20 per cent contained.