Eighteen members of the family along with Bangabandhu's wife Sheikh Fazilatunnesa Mujib, three sons -- captain Sheikh Kamal, lt Sheikh Jamal and Sheikh Russell--, two daughters-in-law -- Sultana Kamal and Rosy Jamal --, brother Sheikh Naser, peasant leader Abdur Rob Serniabat, youth leader Sheikh Fazlul Haq Moni and his wife Arzu Moni, Baby Serniabat, Sukanta Babu, Arif and Abdul Nayeem Khan Rintu were killed on the fateful night.
Bangabandhu's military secretary col Jamil Uddin Ahmad (Bir Uttam), who was later promoted posthumously to the rank of brigadier general, was also killed during the massacre. Some members of a family at Mohammadpur in the capital were killed by artillery shells fired by the killers on the same day.
The day was a public holiday.
The prime minister paid homage to the Father of the Nation by placing wreaths at the portrait of Bangabandhu in front of Bangabandhu Memorial Museum at Dhanmondi Road No 32 in the morning.
After placing wreaths, the prime minister stood there in solemn silence for some time showing respect to the great leader and the great architect of Bangladesh's independence.
A smartly turned out contingent of Bangladesh Armed Forces gave state salute, while bugle played the tune of grief and somber to the last post.
A munajat was also offered seeking the eternal peace of the departed souls of the August 15 carnage.
After paying tributes to Bangabandhu, the prime minister along with her daughter, Saima Wazed Hossain, visited the historic residence of Bangabandhu, which has now been turned into Bangabandhu Memorial Museum, and stayed there for some time.
Later, the place was opened to public to pay their homage to Bangabandhu. People from all walks of life and professions started paying tributes to the Father of the Nation from 8:30am.
From Dhanmondi, the prime minister went to Banani Graveyard where her mother Bangamata Fazilatunnesa Mujib, brothers Sheikh Kamal, Sheikh Jamal and Sheikh Russell, and other martyrs of 15 August were laid to eternal rest.
The prime minister placed wreaths and spread petals on their graves.
She also offered Fateha and doa seeking the eternal peace of the departed souls of the martyrs of 15 August.
Meanwhile, president M Abdul Hamid hosted a milad and doa mahfil at the Darbar Hall of Bangabhaban after Asr prayers, marking the day.
After the milad, a special munajat was offered seeking eternal peace of the departed souls of the Father of the Nation and his other family members.
Tributes were paid to Bangabandhu by placing wreaths at his mazar at Tungipara in Gopalganj district around 10:00am followed by offering fateha and a special doa mahfil there.
The government, different socio-cultural, political and professional organisations, including ruling Awami League and its associate bodies, also marked the day with various programmes maintaining the social distancing rules due to the prevalence of coronavirus.
A special munajat was offered after Zohr prayers in all mosques across the country while special prayers were arranged in temples, pagodas, churches and other worship places across the country.
Bangladesh Betar, Bangladesh Television and private TV channels and radio stations aired special programmes highlighting the life, struggle and achievements of the great leader while newspapers brought out supplements on the occasion.
The national flag was hoisted half-mast at government, autonomous, semi-autonomous, educational institutions, private buildings and Bangladesh missions abroad.
Bangladesh missions abroad also observed the day with elaborate programmes.