Three workers are trapped following a mishap at the Light Rail Transit (LRT) extension project in Puchong this evening.

The Fire and Rescue Department said the victims were buried due to the "collapse of liquid concrete" at the worksite.

One of the workers was found dead at 10pm today, project owner Prasarana Malaysia Bhd said.

Prasarana initially said four were trapped but in a 9.29pm update said one was found at the on-site workers' accommodation.

Rescue personnel are still trying to save two Bangladeshi workers and an Indonesian worker, it said.

Four other construction workers sustained minor injuries in the 4.20pm incident and were sent to hospital, it said in an earlier statement.

The incident occured at the depot of the Ampang LRT extension project site at Kampung Kuala Sungai Baru near Putra Heights, Prasarana said in a statement.

"The formwork and scaffolding collapsed during the concreting of the deck slab," it said.

The scaffolding was professionally-design and certified safe, it said.

"The cause of the incident is still being investigated."

Prasarana director Zohari Sulaiman is on site and expresses his regret.

In August, three Bangladeshi workers perished when a 300-tonne concrete span collapsed at the MRT worksite near the former Rubber Research Institute (RRI) in Kota Damansara.

Previous rail worksite mishaps:

March 29, 2013 – A motorist was killed and another injured when construction equipment fell from a crane at the LRT extension site near Subang Airport.

June 24, 2014 – A metal slab at the Pusat Bandar Damansara MRT construction site falls on a BMW and the driver sustains minor injuries.

June 26, 2014 – Two motorists were injured near Jalan Lapangan Terbang Subang when several metal rods hoisted by a LRT construction crane fell on the car.

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