Excuse me, why did Siqi hit the wall and die in A Dream of Red Mansions?

Siqi has been exiled to her home for a year. Mrs. Wang decided to marry her son Fei Xing, who was in charge, and forced the chess mother to agree that the sedan chair would carry people today. Si Qi longed for Pan Youan and refused to marry Fei Xing. Her mother locked her in the house. Pan Youan came back and smashed the door lock to meet Siqi. When they tried to escape, they were stopped by Siqi's mother and Zhou. Siqi knelt down and begged her mother to let him go, and her mother shed tears in pain, but her wife was in charge and could not resist. Zhou Rui's family shouted "Catch the fugitive slave Pan Youan"! Fei's bride's sedan chair was blown to the door, and Fei Xing, the groom, tried to carry Siqi into the sedan chair, but Siqi refused and crashed into the wall and died. Pan Youan committed suicide and fell beside Siqi.