One of 39 people injured in Wednesday's horrific bus crash in Sheung Shui remained in critical condition on Thursday, while 12 others are still hospitalized.

Six people — three men and three women aged 31 to 59 — died in the crash, in which a double-decker bus smashed through road barriers and hit a tree on the Fanling Highway while traveling from Wan Chai on Hong Kong Island to Fanling.

It was the deadliest traffic accident in Hong Kong since February, 2018, when 19 passengers were killed and 66 others were injured in another bus crash in Tai Po.

The Kowloon Motor Bus vehicle, on Route 978, was towed to a government inspection center on Thursday for further investigation.

Officials of the Highways Department inspected the site of the crash as police investigations continued.

According to the police, no traces of braking were found at the scene. The Highways Department said it did not receive any report of unusual road conditions before the collision.

Among those killed was a female worker of the Social Welfare Department, who was on her way back to her office from an outside assignment.

Secretary for the Civil Service Joshua Law Chi-kong and Secretary for Labour and Welfare Law Chi-kwong extended their deepest condolences to her family on behalf of the civil service.

The SWD has assigned a social worker to each family of the deceased, as well as the injured passengers, to offer psychological counseling, emotional support and financial aid, including assistance in burial services.

The department will also coordinate in arranging donations to the victims' families from charitable organizations.

The Legislative Council's transport panel expressed concern over the crash, saying it will follow up on future bus safety measures to be taken during meetings early next year.

A member of the panel, lawmaker Michael Tien Puk-sun, urged the government to enact legislation requiring all passengers on the upper deck of buses to buckle up.

According to Patrick Wong Chi-kwong, assistant commissioner for transport (bus and railway) of the Transport Department, there are more than 6,000 public franchised buses in Hong Kong. Up to 1,100 of the vehicles are expected to be equipped with safety belts next year, and the rest within three years.

Wong said the Transport Department has asked KMB to complete its report into the crash as soon as possible.

Hong Kong Chief Executive Carrie Lam Cheng Yuet-ngor said on Wednesday the government had already set up a committee to review the safety of franchised buses following last year's fatal Tai Po bus crash, and had made 45 suggestions.

Lam said the government will study whether there's room for improving on those suggestions, which include requiring all newly purchased franchised buses since August, 2018 to install safety belts on every seat, while existing buses are being upgraded with safety belts installed on seats on the upper deck.

A review of the physical structure and maintenance of buses is also being conducted in cooperation with bus manufacturers and depots to improve safety.