The Frankels were wealthy Jewish business people originating from Lithuania and had decided to settle in Singapore after accumulating considerable wealth from their sale of rubber, bread and even furniture in Singapore and around the region. They settled in the estate and developed the area by building roads named after famous Operas of their time including Carmen and Aida, which gave rise to the name of Opera Estate as it is known today. They were influential people that welcomed distinguished guests like Albert Einstein to visit and tour the area. At the onset of WWII the Frankels left for the United States. The area as well as along the wider East Coast Stretch saw machine gun pillbox being installed by the British in anticipation of a sea-bound attack by the Japanese that never materialise. During the Japanese Occupation, the coasts of Siglap and several of the nearby hills were used as execution sites in the Sook Ching operation carried out by the Japanese to clear out anti-Japanese personnel, the operation mostly targeted the Chinese population. At the end of the war many mass graves had been found in the area, one of such place was near the junction of Bedok South Avenue 1 and Upper East Coast Road. In 1953 during the heydays of Singapore film making, Cathay-Keris Studio, one of two major film companies in Singapore, set up its studio along Jalan Keris and the surrounding area was commonly used for shooting scenes in the films. In 1962 a huge fire broke out at Kampong Siglap when firecrackers were burnt out of control and set the village ablaze. The few HDB flats built in the area were built in the aftermath of the fire to house the homeless victims. Starting from the mid-1960s, the Government embarked on an ambitious land reclamation project that saw the coastline of the entire East Coast Region shift outwards. As a result, many villagers in the area could not depend on fishing as a form of livelihood and many eventually settled away or were relocated to the neighbouring estates. The reclaimed land was then redeveloped with numerous high rise flats built and the East Coast Parkway was also constructed. The area has throughout history been home to several of Singapore's Presidents, including the first President of Singapore, Yusof Bin Ishak. The terrain of Siglap can be divided into two, the inland and the outer coastal areas, with the former considerably hilly while the latter because it had mostly been reclaimed generally flat. The uneven terrain inland can be seen with the steep descent of Fidelio Street into the lower lying areas of Opera Estate at the Fidelio Circus.