"Now, they had beds upon which travelers slept. If he [the guest] was too long, they shortened him [by cutting off his feet]; if too short, they stretched him out...If a poor man happened to come there, every resident gave him a denar (coin), upon which he wrote his name, but no bread was given to him. When he died, each came and took back his denar...A certain maiden gave some bread to a poor man, [hiding it] in a pitcher. Once the matter becoming known, they daubed her with honey and placed her on the parapet of the wall, and the bees came and consumed her. Thus it is written (Genesis 18:20), ‘And the Lord said, The cry of Sodom and Gomorrah, because it is great:’ whereon Rab Judah commented in Rab's name: On account of the [cries of the] maiden" (Talmud Sanhedrin 109a).
It was not only outsiders to whom the people of Sodom demonstrated their corrupt sense of morality:
“Rabbi Levi said: [God said]: ‘Even if I wished to keep silent, justice for a certain maiden does not permit Me to keep silent’ For it once happened that two damsels went down to draw water from a well. Said one to the other, ‘Why are you so pale?’ ‘We have no more food left and are ready to die [from starvation],’ replied she. What did she do? She [the other maiden] filled her pitcher with flour and they exchanged [their pitchers], each taking the other’s. When they [the Sodomites] discovered this, they took [the maiden who helped her friend] and burnt her” (Genesis Rabbah 49:6).
The people of Sodom weren’t just stingy, they were outright malicious to those in need. God destroyed the city because the city represented the true and utter perversion of justice in the world.