Around 100 people were attending the “Backesfest” when the incident happened at a fried potatoes stand around noon on Sunday.
According to a police spokesperson, a 67-year-old woman died as a result of severe burns on Monday.
A total of 14 people were injured and given treatment at the scene. Five people between the ages of 31 to 75-years-old are in a critical condition
They suffered severe burns, while one of them suffered a heart attack.
According to initial findings, the incident could have been caused by fat exploding in a large grill frying pan.
Some of the damage at the festival. Photo: DPA
Authorities on the scene told public broadcaster WDR that more than 100 people were at the event when the explosion happened.
Those who suffered injuries were transported by emergency helicopter to hospitals in the larger nearby cities of Dortmund, Cologne and Bochum.
Investigators were on Monday probing exactly how the accident happened.
The festival was taking place on the 675th anniversary of the village of Alchen.