The ice was relatively still for the rest of the month. On 20 October, steam was raised again and the engines tested. On 22 October, the temperature dropped sharply from to and the wind veered from southwest to northeast. This caused the loosening pack to compress against the Antarctic coast once again. On 23 October, pressure ridges could be seen forming in the ice and moving near the ship. The next day a series of pressure waves struck the "Endurance", causing the ice around the ship to fracture into separate large pieces which were then tumbled and turned in all directions. The ship was shunted back and forth before being pinched against two floes on her starboard side, one at her bow and one at her stern, while on the port side a floe impacted amidships, setting up a huge bending force on the hull. Parts of the rigging were snapped under the strain.