Spectral glow appears in night along Florida highway, photos show. What caused it?

Scary things occasionally stumble onto Florida’s highways in the dark, but it literally was the ground that began glowing in Glades County, photos show.

The fluorescent shimmer was discovered around 11 p.m. on Saturday, Jan. 11, near the intersection of State Road 29 and County Road 74, and an equally sinister blue smoke hovered above.

It didn’t take long for commenters to bring up aliens when photos were shared on Facebook.

However, Glades County Public Safety had a more down-to-earth explanation: It was a chemical fire.

A hazardous materials team was sent to investigate and discovered “sulfur-based fertilizer known for producing a glowing effect while burning.”

The Fort Myers Fire Department reports it took five hours — 11 p.m. to 4 a.m. — for first responders to “contain and mitigate” the fire.

“Initial actions included isolating the area, identifying the hazardous product, and addressing the fire’s unique glow effect,” Fort Myers fire officials said.

The creepy glow was caused by the sulfur, officials said. Tests showed the compound contained 10% sulfuric acid, along with sodium perchlorate, which is toxic when ignited, NOAA.gov reports.

“If large quantities are involved in a fire ... an explosion may result,” NOAA.gov says. “Inhalation, ingestion or contact (skin, eyes) with vapors or substance may cause severe injury, burns or death. Fire may produce irritating, corrosive and/or toxic gases.”

The cause of the fire is under investigation, but “there is currently no indication of foul play,” Glades County officials said.

Glades County is about a 130-mile drive northwest from Miami.

This story was originally published January 16, 2025 at 2:28 PM.