SINGAPORE - The safety devices of the lift that severed an elderly woman's left hand last month have been found to be in working order, according to the final investigation report submitted to the Building and Construction Authority (BCA).

"All the door protective devices were tested and verified to be working according to their specifications," said the BCA in a statement on Friday (Nov 6), citing findings from the report submitted by an authorised examiner (AE).

"The door protective devices cannot be proven reasonably to have failed to function properly on the day of the incident," the BCA added.

The report also provided a reconstruction of how Madam Khoo Bee Hua, 85, could have lost her hand on Oct 9 when she was in the lift of her Tah Ching Road block.

The Jurong resident had boarded the lift, but the doors had closed on her dog's leash before the pet could enter. When the lift began ascending, the leash around Madam Khoo's left wrist tightened.

Said the BCA: "Based on the AE's simulation, it is likely that the pull of the taut leash could have caused a fulcrum action, opening up a small gap at the base of the lift cabin doors.

"Her left hand, which was partially pulled through the lift cabin doors, was crushed and severed between the lift cabin doors and the internal parts of the lift lobby doors (between the inner and outer lift doors) before the lift came to a gradual stop."

Madam Khoo's hand subsequently fell to the bottom of the lift pit when the dog leash was released, the report added.

The AE recommended stepping up public education on the safe use of lifts and working with industry players to review the settings of various lift safety devices.

The BCA said it had reviewed the report, and conducted its own independent investigation about the accident. Its findings were consistent with the examiner's, it added.

The authority also said that it has accepted the recommendations put forth by the examiner.

Madam Khoo's son, who viewed a preliminary version of the report on Thursday morning, told The Straits Times that the findings made him question if "this may mean that the standards are too low, as they cannot protect the safety of the passenger".

He also wondered why the lift was cleaned before the examiner viewed the scene.

That meant that no bloodstains or bone fragments were admitted as evidence, he said.

He recalled that when his younger daughter returned to Block 322 to retrieve her grandmother's identity card from her flat there about two hours after the incident, she noticed that the lift had been cleaned completely.

"They should have left the scene as it was until the examiner inspected it. I'm very uncomfortable about this," said Mr Lee, adding that he has been left frustrated by the report.

He also said that his mother spoke to him for the first time on Thursday about her ordeal, and was still "puzzled" as to how her hand was trapped between the doors.

"She said it was so fast, just two seconds. She remembers trying to use her stick to open the doors and pull her hand out."

Madam Khoo, who also broke her left leg when she fell inside the lift, is still recovering at Jurong Community Hospital.

She is expected to remain there for another 10 weeks or so.

Jurong Town Council general manager Ho Thian Poh said in a statement that their insurer AXA has offered to assist Madam Khoo with her medical charges and post-hospitalisation homecare support.

"Our town council, working together with the community, will ensure Madam Khoo and her family have all the help they need to recover following this traumatic incident."

Deputy Prime Minister Tharman Shanmugaratnam, who is adviser to Jurong Grassroots Organisations, said he was glad that AXA had stepped forward to assist the family.

Mr Tharman, who has known Madam Khoo and her late husband for 14 years, added that he had visited the victim in hospital earlier this week and that she was her "usual indomitable self."

"The doctors and nurses who are treating her are inspired by her determination to get back to as much of her active and independent life as possible," he said.