Captain Backer relates the incidents of that evening which ended with the burning of the city. At 1030 hours a German representative appeared with an ultimatum, unsigned and without any indication of the sender, demanding that the Dutch capitulate before 1230 hours. This document was returned by the Dutch colonel, who asked to be told the name and the military rank of the officer who had called upon him to surrender.
At 1215 hours Captain Backer appeared before the German lines and was received by a German officer. At 1235 hours he had an interview with German officers in a dairy shop. A German general wrote his terms for capitulation on the letter of reply, which the representative of the Dutch General Staff had just brought to him.
At 1320 hours Captain Backer left the place, this dairy shop where the negotiations had taken place, with the terms to which a reply had to be given. Two German officers escorted him. These escorting officers were protected by the flight of German aircraft, and red rockets were fired by them at 1322 and 1325 hours. At 1330 hours the first bomb fell upon Rotterdam, which was to be completely set on fire. The entry of the German troops was to take place at 1850 hours, but it was put forward at 1820 hours. Later the Germans said to Captain Backer that the purpose of the red rockets was to prevent the bombing. However, there had been excellent wireless communication from the ground to the aircraft. Captain Backer expressed his surprise that this should have been done by means of rockets.
The work on the inundation of the “Wieringermeer” polder began on 9 and 10 April 1945. I quote a Dutch document. That day German soldiers appeared on the polder, gave orders, and placed a guard for the dyke.
“On 17 April 1945 at 1215 hours the dyke was dynamited so that two parts of it were destroyed up to a height somewhat lower than the surface of the water of the Ijesselmeer . . . .
“As for the population, they were warned during the night of 16 to 17 April”—that is, at the time when the water was about to flood the polder—“In Wieringerwerf the news received by the mayor was passed from house to house that at noon the dyke would be destroyed. Altogether for this great polder, with an area of 20,000 hectares, not more than 8½ to 9 hours were granted for evacuation . . . . Telephone communications had been completely interrupted; and it was impossible to use automobiles, which meant that some individuals did not receive any warning until 8 o’clock in the morning . . . .
“The time given to the population was, therefore, too short for the evacuation . . . .