After early July 1941, people in the Netherlands could no longer obtain visa for the United States, so neither could Otto and his family.
Otto had applied for entry to the United States in 1938. Because many Jews wanted to flee Germany after 1938, there were so many applications that it took a very long time before his application was processed.
On 14 May 1940, the consulate in Rotterdam was destroyed in the heavy bombardment of the city. As a result, all records were lost. All applicants had to collect and resubmit the required documents. To make matters worse, the American government had become stricter because it feared letting in German spies.
Otto, too, continued with his application, but he suffered a severe setback. Every immigrant had to be interviewed at the American consulate as part of the application, but in July 1941, the consulate in the Netherlands was closed. Even if he had been invited for an interview, he would have had to go to a consulate in Southern Europe. And that had become impossible by then.
Otto started another application for visa for Cuba. This was cancelled on 11 December 1941. After that, he had no real options left for taking his family to a safe country.