Shortly before 1 PM yesterday, a series of explosions in Sioux City, Nebraska left a grain elevator destroyed and a worker in serious condition. The police evacuated dozens of people from their homes in a six-block radius—they are not expected to return until later this afternoon.
Authorities report that 3 workers were near the grain elevator when an explosion that sounded like "thunder" left a gaping hole in the side of the elevator. One of the workers was taken to a hospital in Sioux City (and later Lincoln), while the other two were left with slight or negligible injuries. The grain elevator reportedly belongs to Andersen Farms.
Witnesses say they saw two distinct explosions: an initial one that blew the top off the elevator, and a larger one that ripped a hole in the sidewall—others described this explosion as a "fireball." The explosion was felt by residents up to 2 blocks away.
The South Sioux City Police Chief Ed Mahon has reported that the cause of the explosion remains undetermined. Firefighters continued to fight flames for hours while a gas company shut off gas power to the facility. A two-man task force from FEMA arrived to aid Sioux City first responders. City Council also declared a state of emergency, making federal aid available to the displaced residents and closed businesses.
Grain Elevator Explosions
According to the statistics, up to 11 grain dust explosions will occur this year. Over the last few decades, grain elevator explosions have been responsible for the deaths of 180 people and the harm of 675 more. The cause of these explosions is normally from the combustion of extremely fine dust particles in the air. The dust and the air mix together into a sort of fuel, which only requires an igniter to create a chain of combustion—creating an explosion.
Under these conditions, just a spark would be enough to create an enormous fireball like the residents in South Sioux City witnessed. Experts recommend regularly cleaning grain elevators in order to prevent dust from collecting and increasing the chances of a spontaneous explosion.