The aircraft was Mi Amigo - Spanish for 'my friend' - flying with the 364th Bomb Squadron of the 305th Bomb Group, based at RAF Chelveston in Northamptonshire. On the morning of 22 February she had set out for a raid over Aalborg in occupied Denmark and had been mauled by Luftwaffe fighters. The men trying to bring her home that afternoon were nearly all in their early twenties. First Lieutenant John Kriegshauser, 23, was the pilot. Second Lieutenant Lyle Curtis was co-pilot. Second Lieutenant John Whicker Humphrey navigated. Second Lieutenant Melchor Hernandez was the bombardier. Staff Sergeant Harry Estabrooks was flight engineer and top turret gunner. Staff Sergeant Robert Mayfield handled radio and photography. Sergeant Charles Tuttle worked the ball turret, slung beneath the belly of the plane. Sergeants Vito Ambrosio and George Malcolm Williams were the waist gunners. Sergeant Maurice Robbins was in the tail. Ten young men, ten names. The pilot would later receive a posthumous Distinguished Flying Cross.

What happened in the final seconds has been told many ways. The popular Sheffield version - the one that crystallised in the city's memory and that Tony Foulds carried with him for most of his life - is that the crew saw the children in the open meadow of the park and steered away to spare them, choosing the wooded hillside instead. Modern researchers, working from squadron records and the few surviving witness statements, have suggested the picture was more complicated: Mi Amigo was badly damaged, control was failing, the crew may have been trying simply to ride her down. Either way, what mattered was visible from the path: the plane could have come down in the meadow where the children were playing and did not. Twelve trees had to be cut down on the ridge after the crash. Some of the surviving trees still carry burn marks on their upper branches, visible in winter when the leaves are gone.

The site was quiet for a quarter century. Then on 30 November 1969 a grove of ten scarlet oaks - Quercus coccinea, one for each man - was planted on the hillside behind the park café. A boulder was set among them, carrying two bronze plaques. The upper plaque, erected by the Sheffield branch of the Royal Air Force Association, names the ten crew under the RAF motto Per Ardua Ad Astra. The unveiling was attended by the Lord Mayor of Sheffield, the Bishop of Sheffield, and Major General John Bell of the US Third Air Force in Britain. For decades after, the memorial was looked after by local air cadets and the Friends of Porter Valley. Tony Foulds began maintaining it himself in earnest from 2018. His care is modest and constant: sweeping the path, watering the flowers donated by garden centres and well-wishers, talking with the visitors who come up the slope to read the names.

In January 2019, BBC Breakfast presenter Dan Walker met Tony in the park and learned of his wish for a commemorative flypast on the 75th anniversary. The story spread. At 8:45 on the morning of 22 February 2019, thousands of people gathered around the memorial as ten aircraft passed over Endcliffe Park in formation - an RAF Dakota from the Battle of Britain Memorial Flight at Coningsby, an MC-130J Commando II and a CV-22 Osprey from Mildenhall, a KC-135 Stratotanker, two RAF Typhoons, and four USAF F-15E Strike Eagles from Lakenheath flying the missing-man formation. The names of all ten crew had been painted onto the F-15Es. Relatives of the dead airmen stood beside Tony Foulds in the cold morning. A second flypast marked the 80th anniversary in February 2024. The boy who had waved at the falling plane was eighty-seven years old. He was still there to see it.