Durham city officials, developers, and community leaders will gather on Oct. 23 to mark the groundbreaking of Phases III and IV of the Lofts at Southside, a project aimed at adding 100 affordable housing units to the Southside neighborhood. The event, organized by the City of Durham and development partner McCormack Baron Salazar, Inc., is scheduled to take place from 9 to 11 a.m. at 703 South Roxboro Street.