Illinois semitruck crash causes 5 fatalities and an ammonia leak evacuation for residents

– Semitruck carrying 7,500 gallons of ammonia overturns in Illinois.

– Multi-vehicle crash leads to five fatalities and five hospitalizations.

– Evacuation of 500 people within a one-mile radius due to ammonia leak.

– Approximately 4,000 gallons of ammonia released; leak partially patched.

– Effingham County officials describe the situation as "very serious" and "fluid."

– Large plume from ammonia leak creates dangerous air conditions.

– Effingham County Sheriff orders evacuation in northeast Teutopolis.

– Emergency responders face challenges due to hazardous air conditions.

– National Transportation Safety Board to investigate the crash.

– Inhalation of anhydrous ammonia can be fatal; substance described as "terrible."