Divers were last evening searching for a Water and Sewerage Authority (WASA) employee and another man who disappeared in the Navet Reservoir yesterday.
Anthony Warrick, a security officer employed at WASA, and Basdeo Ramlal were among 13 people on a single-engine vessel conducting depth samples and routine maintenance of the dam.
Ramlal, who lives in a community near the reservoir, accompanied the WASA officials, police said.
The Sunday Express was told that Warrick's wife was also on board the vessel.
WASA's head of Corporate Communications Ellen Lewis stated the vessel overturned around 11 a.m.
Up to late last evening, Coast Guard divers were searching for the missing men.
Officers attached to the Brasso Police Station were also at the scene conducting investigations.
"Two persons are unaccounted for, one of whom is a WASA employee whilst the other is a resident of the area," Lewis stated.
Three people were taken to the San Fernando General Hospital and remained in stable condition.
Lewis stated, "Relatives of the missing persons, as well as those at hospital, are being kept abreast of the situation. WASA will be providing counselling and other forms of support to the relatives of those involved.
"The boat used in the expedition was a single-engine vessel, usually used by authorised personnel to conduct depth samples and for routine maintenance of the dam."
The Navet Reservoir has a depth of 44 feet and storage capacity of 4.2 billion gallons.
It supplies San Fernando, Debe, Penal, Princes Town, Rio Claro, South Oropouche, La Brea, Moruga, New Grant, Plaisance Park, La Romaine and Fyzabad.