COLUMBUS, Ohio — Freight cars packed with ethanol exploded after derailing early Wednesday, prompting a rapid evacuation of an urban neighborhood.
The National Transportation Safety Board dispatched a 10-person team to investigate the derailment on the Norfolk Southern Corp. tracks, which led to spectacular explosions and the burning of three rail cars, each carrying 30,000 gallons of ethanol.
Two people were slightly injured.
Officials said they do not know yet what caused the accident, which occurred around 2 a.m. in an industrial area near Interstate 71, north of downtown. The explosions were felt for blocks.
Columbus Mayor Michael Coleman, who visited a temporary Red Cross shelter set up for evacuees, said the accident could have been worse.
‘‘I’m grateful, in one respect as well, that this did not occur in a more populated area,’’ he said. ‘‘It very well could have. A mile up or a mile south. North or south, east or west. It could have been tragic in other ways as well.’’
The two people were injured while walking on the tracks to investigate when a second explosion occurred. Officials said they went to the hospital themselves with minor injuries.
Assistant Chief David Whiting of the Columbus fire division said it was fortunate the accident occurred in the middle of the night.
‘‘The time it occurred, where it occurred, were very good things for us,’’ Whiting said. ‘‘Because we didn’t have a whole lot of people around, businesses were closed, we were able to take care of getting our firefighters back and evacuating a small number of people.’’
About 100 residents who live within a 1-mile radius of the derailment were evacuated by firefighters, who decided to let the fire burn itself out, according to Whiting.
Officials said the burning ethanol, an alcohol compound commonly used in fuel, posed no environmental or health concerns. Residents were back in their homes by midafternoon.
Nicholas Goodrich, 35, a grocery store employee from Columbus, said he and two other people got as close as 100 feet from the explosion.
‘‘Looking at it, I thought it was an atomic bomb or something,’’ he said.
‘‘The heat was so excruciating that I had to ball up and cover my body.’’