The catastrophic flooding event known as Saint Marcellus's flood occurred due to a combination of adverse weather conditions, including a powerful storm that brought heavy rains and strong winds. The surge of water overwhelmed the existing dykes and sea defenses, which were inadequate for such a monumental tidal wave. Coastal communities, particularly in what is now known as the Netherlands and Germany, faced unprecedented devastation as the waters rose, inundating villages and displacing thousands.

In the aftermath, the human toll was staggering, with reports estimating that around 25,000 lives were lost. This figure includes a significant portion of the population from Frisian towns along the North Sea's coast. The flood not only claimed lives but also destroyed homes, farmlands, and crucial infrastructure. Survivors faced immense challenges in rebuilding their lives, as the once-fertile coastal plains became submerged or permanently altered in the flood's wake.

The event was so impactful that it led to long-lasting effects on both the geography and the economy of the region. Rebuilding efforts sought not only to restore what was lost but also to improve defenses against future floods. The tragedy became ingrained in the collective memory of the coastal populations, influencing policy decisions regarding sea defenses and disaster preparedness for generations to come.