This paper studies distributed event-triggered broadcast in networked control systems (NCSs) with transmission delays and packet loss. We propose a triggering scheme for each agent to determine when it broadcasts its local information. The assumption of consistent broadcast states in the prior work is relaxed. The shortest broadcast periods (SBPs) and the maximal allowable transmission delays (MATDs) under this scheme are greater than a positive constant. We show that if the weighted sum of all SBPs, MATDs, and maximal allowable numbers of successive dropouts (MANSDs) is bounded by a given positive constant, the event-triggered NCS is asymptotically stable. This result provides the basis for the design of firm real-time NCSs.