The sulfur continued to burn through the night and into Thursday as efforts to extinguish the fire continued. The Environmental Protection Agency also responded to the scene, deploying specialized equipment to conduct air monitoring.

Kentucky Gov. Andy Beshear declared a state of emergency in Rockcastle County on following the derailment and several hundred residents were relocated to a shelter in a nearby middle school after authorities encouraged them to evacuate.

Beshear has also activated the state’s price gouging laws to protect families from grossly overpriced goods and services.

By Thursday afternoon, the blaze had been 50% contained and hopes were high it could be completely contained by the end of the end of the day and the evacuation order lifted, Rockcastle County judge/executive Howell Holbrook said at a press briefing.

CSX director of emergency management and hazardous materials Joe McCann told reporters the company’s focus is on helping local officials and residents.

“We have had folks here since the beginning of incident, and our focus in on supporting the local responders and supporting the community members that are impacted,” he said, adding that the cause of the derailment remained unknown as is still under investigation.

The accident prompted authorities to close U.S. Hwy. 25 in both directions from the Laurel County line to Calloway Branch Road on Wednesday.