Crowded conditions can lead to violence. Although these incidents happened in a state prison in California, overcrowding in any jail or prison is a condition that could lead to violence.
From the LA Times:
2 Inmates Killed in Lancaster
Some prisoner rights activists say crowding may have been a cause of the deaths.
By Amanda Covarrubias, Times Staff Writer
Two inmates have been slain over the last three weeks inside a cellblock at the Lancaster state prison, renewing concerns about overcrowding at the institution.