Three men, including two workers and a contractor, died due to suffocation inside a manhole at Kalundre node in Panvel on Wednesday evening. Senior police inspector Vinod Chavan said when the labourers did not come out of the manhole, the contractor entered it to check and then did not return himself. Bystanders informed the fire station and personnel reached the spot. The bodies were retrieved and sent to Panvel rural hospital for post-mortem. The contractor, employed by CIDCO, was identified as Vilas Mhaskar. The labourers are yet to be identified.