All about what happened to people in Hiroshima blast

HIROSHIMA: The atomic blast in Hiroshima on August 6, 1945 killed 140,000 people; tens of thousands died instantly, while the rest succumbed to injuries or illness in the weeks, months and years afterwards.

The first thing people noticed was an "intense ball of fire" according to the International Committee of the Red Cross (ICRC).

The atomic bomb had a yield of 15 kilotonnes, equal to 15,000 tonnes of TNT, yet was 3,300 times less powerful than the biggest hydrogen bomb tested by the Soviet Union in 1961.

Temperatures at the epicentre of the blast reached an estimated 7,000 degrees Celsius (12,600 Fahrenheit), which caused fatal burns within a radius of about three kilometres (five miles).

ICRC experts say there were cases of temporary or permanent blindness due to the intense flash of light, and subsequent related damage such as cataracts.

A whirlwind of heat generated by the explosion also ignited thousands of fires that burned several square kilometres (miles) of the largely wooden city. A firestorm that consumed all available oxygen caused more deaths by suffocation.

It has been estimated that burn and fire-related casualties accounted for more than half of the immediate deaths in Hiroshima.

The explosion generated an enormous shock wave and almost instantaneous expansion of air which also caused a huge number of deaths.

Some people were literally blown away while others were crushed inside collapsed buildings or perforated by flying debris.

The ICRC recorded many victims with ruptured internal organs, open fractures, broken skulls and penetration wounds.

Another deadly effect of the atomic bomb was the emission of radiation that proved harmful in both the short and long term.

Radiation sickness was reported in the attack's aftermath by many who survived the initial blast and firestorm.

Acute radiation symptoms include vomiting, headaches, nausea, diarrhoea, haemorrhaging and hair loss. Radiation sickness can lead to death within a few weeks or months.