Two sanitary workers and a restaurant employee died of asphyxiation after inhaling toxic gases while cleaning the drainage at a restaurant in Pondur near Sriperumbudur in Kanchipuram district, say reports. The deceased sanitary workers were identified as Murugesan, Ajith, while the restaurant employee was identified as Ravi, reports added. Further, two more sanitary workers are in a critical condition and have reportedly been admitted to hospital.