The worst blow was yet to come: On March 22, 1944, another British air raid of 816 aircraft destroyed large parts of the old town that had previously been spared, including all churches except the Old Nikolaikirche and Leonhardskirche. According to official information, 500 air mines, 3,000 heavy explosive bombs and 1.2 million incendiary bombs were dropped on the city in just under an hour, with a clear focus on the city centre. As with previous air raids, this was part of the tactic: the majority of all houses in the old town were built in half-timbered construction, so that they largely burned completely in the unleashed firestorm. But patrician buildings from the Middle Ages built of stone, such as the canvas house or the stone house, were also destroyed by explosive devices. This air raid is also reproduced in a chalk drawing by the painter Karl Friedrich Lippmann, who painted what was happening on the Sachsenhausen side. The drawing shows how the old town and sky are brightly lit due to the fire. The artist's house and emergency shelter were also bombed out.