World War II in Pictures- "The German ultimatum ordering the Dutch commander of Rotterdam to cease fire was delivered to him at 10:30 a.m. on May 14, 1940. At 1:22 p.m., German bombers set the whole inner city of Rotterdam ablaze, killing many of its inhabitants." (Aerial view of the ruins of Rotterdam)

On Tuesday May 14, 1940 (OTL), Rotterdam was bombarded by the Luftwaffe(German Air Force). 800-900 people were killed - mainly civilians. Over 80,000 people lost their homes and more than 25,000 houses and buildings were destroyed. The fires that raged on after the bombardment, ate their way through the city for weeks.