Closer in towards Winson Green the effects of the heat from the fireball were more pronounced. The foliage in the countryside had crisped as if autumn had arrived. Smaller brushwood was smouldering. Haystacks were burning and paintwork on buildings and vehicles in the path of the heat-wave blistered. At Aldridge, and at other places within about twelve kilometres of the fireball, people caught in the open received burns which needed immediate hospital treatment. At this range curtains and other materials inside rooms that were exposed to the heat pulse began to smoulder and in some cases burst into flames. Any lightweight objects such as newspapers, canvas and empty packaging in the open soon caught fire.
Closer to the fireball heat levels became even more intense, so that almost any lightweight material subject to the heat-wave burst into flame while metals and other objects were scorched and distorted. At these ranges the clothing worn by individuals no longer gave effective protection against the heat. Clothes burned off, and people in the open received such extensive burns that their prospects of recovery, even with first-class medical assistance, were negligible. Fires were started inside and outside buildings to an increasing extent as the epicentre was approached, with apparently almost total conflagration occurring within three to four kilometres of Winson Green.
The enormous blast pressures released by the nuclear device followed the heat-wave within a matter of seconds. Those in the open who had suffered severe burns had no more than a few seconds in which to register shock before the blast-wave hit them. Those inside buildings who had already experienced the overpowering flash of light were now subject to the effects of blast. Within a second or so of the detonation the blast-wave hit the city centre beneath the fireball. The enormous pressures had the effect of instantly crushing all buildings below it so that what remained was only a levelled mountain of rubble. The blast-wave then roared and crushed its way outwards from the centre utterly destroying everything in its path. No structures above ground level were able to withstand the tremendous pressures and the coincident wind speeds resulting from the blast. Within three kilometres of Winson Green nothing survived, every building and structure being reduced to rubble and strewn across the roads so that the entire area looked like a gigantic rubbish heap. The effects of the blast-wave began to decline as it travelled outwards, so that between three and six kilometres from the centre a few of the smaller and more strongly constructed buildings remained standing, some at crazy angles and missing many portions of softer construction around reinforced concrete or steel skeletons. Even these few remaining buildings were in such a twisted and derelict condition that they were hardly recognizable as the original structures. They were surrounded by the gutted remains of lighter buildings of modern construction such as hospitals and schools, demolished beyond recognition. All domestic structures within this area suffered similarly, with most brick houses collapsing under the effects of the blast-wave.
Those who had suffered the most agonizing effects of the heat-wave were mercifully killed by the blast-wave that followed. People who had been indoors were now buried beneath mountains of rubble and suffered a similar fate. Within three or four kilometres of Winson Green very few people survived the immediate effects of the detonation. Outside this range, and up to about seven or eight kilometres away, the collapse and destruction of most buildings trapped people in hundreds under fallen masonry. There were many deaths and severe injuries beyond counting. The air was full of flying objects, picked up by winds moving outwards from Winson Green at speeds which, even at ranges of four or five kilometres, approached 500 kilometres per hour. The wind drove along objects standing in its path like confetti. Motor cars and other vehicles were bowled over and over, carried tens and even hundreds of metres from where they were. People caught in the open were picked up, flung through the air and dashed against any solid object in their path. Roof tiles, pieces of masonry and any loose objects were projected through the air like missiles, smashing their way through obstructions and causing injury to many. At distances greater than seven or eight kilometres from the centre damage levels began to fall off, but even so all lightweight structures were blown over, roofs were blown off and higher masonry buildings suffered extensive damage. Large amounts of rubble and masonry fell into the streets and all windows were blown out, much of the glass being converted into missiles with much injury to people in the way.