A train was derailed at Fields and 5th avenues, leading to an explosion and fire early Wednesday morning just south of the Ohio State Fairgrounds.

Reports indicated that 16 cars derailed at about 2 a.m. and the cause of the derailment is still unknown. The Norfolk Southern train had been heading to Linwood, N.C., when it derailed while passing through Columbus.

More than 15 hours later, three cars containing ethanol continue to burn, according to a Norfolk Southern Corporation release. They will burn for an undetermined amount of time.

Onlookers described the early morning explosion as a light so bright it looked like sunshine.

Officers from the Columbus Division of Police advised people to evacuate the area as they blocked off roads. Evacuation was not mandatory, but it was advised for anyone within a half-mile of the derailment site.

At about 10:30 a.m. Mike McNutt with Columbus Public Health said the evacuation zone had been reduced to a quarter-mile surrounding the site of the explosion.

It has been reported that the evacuation was lifted around 6 p.m.

Two freight cars were also punctured, leaking corn syrup and grain, according to a Norfolk Southern Corporation press release.

The National Transportation Safety Board sent representatives to Columbus to inspect the incident site. After visiting the site, NTSB member Earl Weener spoke in a press conference at about 5:15 p.m.

Weener said NTSB sent “staff with expertise in rail equipment, hazards, materials and emergency response,” to Columbus, and that the team is still gathering details about the derailment.

He said they would hold another briefing later Wednesday evening.

Columbus Division of Fire Battalion Chief Michael Fowler said about 100  people had been evacuated to the Rhodes Center at the fairgrounds Wednesday morning.

It has been reported that two people sustained minor injuries as a result of the explosion, and transported themselves to receive medical attention.

HAZMAT officials were called to the scene early Wednesday morning. The train was carrying chemicals including denatured alcohol and styrene, a chemical used to make plastic. McNutt said “all harmful chemicals” had been removed from the accident scene.

The cars containing styrene were not pierced during the derailment.

OSU coordinator of chemical safety John Herrington said styrene is moderately hazardous to be inhaled or ingested.

“It’s not just the styrene and alcohol, but the byproduct as well,” he said. He called it “generally hazardous” to be inhaling any chemicals or smoke.

McNutt said the alcohol is going to be allowed to burn off for the next few hours, and the situation should be resolved soon.

“It’s a matter of hours, not days,” he said.

Ohio State students received an alert about the fire at 3:45 a.m., and another at 8:45 a.m., warning to avoid the area. Some students however, found out about the explosion sooner.

“I was just sitting on my couch and there was this like huge sunburst. I thought like the sun like had come up for a second, and then I like looked outside and no one acted like anything had happened,” said Christina Sykes, a fourth-year in economics.

Sykes said she turned on the news to find out what was happening, but could see the flames from her house on 16th and 4th avenues.

Andrew Holleran and Emily Tara contributed to this article.