An unanticipated result of the steel fencing installed to secure the previously open gangways at Cabrini–Green was that it became difficult for Chicago police officers to see through the steel mesh from outside. On July 17, 1970, Chicago police patrolman Anthony N. Rizzato and Sergeant James Severin were shot and killed by gang members while patrolling community housing for an all-volunteer "Walk and Talk" project. As the officers proceeded across the Cabrini–Green baseball field, the assailants opened fire from an apartment window. The purpose of the shooting was to seal a pact between two rival gangs. Both officers were killed in the attack. Three adults and one juvenile were later charged with murder. The two shooters were sentenced to 100–199 years in prison for two counts of murder. In 1981, the gang killings of 11 made national attention.