All of U.S.1 along the 18-Mile Stretch in the Florida Keys was closed Tuesday evening due to a wildfire. (Video courtesy: Monroe County Sheriff’s Office)

MIAMI – A wildfire shut down the main artery along the Florida Keys Tuesday evening, leading to major traffic headaches.

All of the 18-Mile Stretch along US 1 was closed as flames roared near the roadway on the Miami-Dade side, closing off all inbound and outbound roads to the Florida Keys.

Video and photos from the Monroe County Sheriff’s Office showed flames near the road and thick smoke billowing in the air.

The road was shut for about four hours, slowly reopening around 8:30 p.m. ET.

The fire has burned about 4,000 acres so far and is 20% contained as of Wednesday afternoon, according to the Florida Forest Service.