Samsung C&T is being probed by Vietnamese authorities over an accident at a construction site that left 13 workers dead and dozens injured, company officials said Tuesday.

Vietnamese police banned several Samsung C&T employees from leaving the country amid an investigation into a scaffolding collapse that took place in the central province of Ha Tinh last week, the South Korean builder confirmed.

“The company received a report on the travel ban from the Vietnamese police. We will cooperate fully with the investigation,” Samsung C&T official Yoon Seung-jae told The Korea Herald.

The ban was applied to 48 Samsung C&T Vietnam employees who were involved in the accident, Nguyen Van An, deputy director of the Public Security Department of Ha Tinh Province, was quoted as saying by Vietnamese media.

The move came after Vietnam’s Prime Minister Nguyen Tan Dung urged his country’s authorities to “deal with it in a serious manner” in accordance with the law.

On March 25, 13 Vietnamese workers were killed and 28 others were injured when a scaffold weighing hundreds of metric tons collapsed at the construction site, where Samsung C&T is the main contractor, in the Vung Ang Economic Zone in central Vietnam.

Vietnam authorities said the initial cause of the collapse was the failure of a hydraulic brake system.

Some survivors told local media that about 30 minutes before the collapse, the scaffolding shook strongly. Many of them ran away, but a few minutes later their supervisor ordered them to come back to continue working.

Samsung C&T president and CEO Choi Chi-hun visited the construction site on the following day and offered initial support of 30 million dong ($1,400) for the families of each victim.

But the company has not yet decided on the actual compensation for the victims, according to the official.

Samsung C&T has been operating the $203 million seaport breakwater project since 2012, with an expected completion date of May 2016.

“We do not know how the accident will affect the completion schedule,” the official said.

By Park Han-na (hnpark@heraldcorp.com)