SINGAPORE - For 30 minutes, the old woman lay on the ground with a bloody wound on the left side of her forehead.
Mrs Tan Kim Yoke, 71, appeared to be trying to reach for her mobile phone in her bag to call for help.
But it remained out of reach and after half an hour, her body went still.
Her final moments were captured by a closed-circuit television (CCTV) camera at the lift lobby of Serangoon North Mapletree Building, where she died on Thursday morning.
Mrs Tan worked there as a cleaner and her body was discovered at about 10.30am.
Speaking to The New Paper at his mother's wake, Mrs Tan's youngest son, civil servant Donald Tan, 32, said security guards told him about what they saw after replaying the CCTV footage.
He watched the first 10 minutes of the footage from the point where Mrs Tan was waiting for the lift with a trolley at the second storey to the point where she fell and hit her head.
"They (the security guards) did not want us to watch the rest (of the video) so that we would not be traumatised by it," said Mr Tan.
"Her legs were wobbly just before she fell and hit her head."
Mrs Tan was discovered by a colleague, who informed security guards and called the ambulance.
Mr Tan was on his way to meet a friend when he got a call about his mother's death.
He said: "I was thinking, 'How can this happen?'"
The news was a shock to Mrs Tan's family, who knew her as an active and healthy woman.
Mrs Tan, who had four sons and who loved travelling, had returned from her holiday in Genting Highlands just a week before.
Mr Tan said his mother became a cleaner at Mapletree after finding her previous job as a hotel chambermaid too strenuous.
She continued working as she liked occupying her free time with work.
He said: "My mum woke up at 4am every day and walked to the MRT station to take a train to her workplace.
"She insisted on working that day because a co-worker took leave and she wanted to help out."
Mrs Tan's eldest son, who declined to be named, said he wished someone in the building had walked past his mother's body earlier.
"I wish one of the security guards had seen her either through the security cameras or during their patrols," he added.
"Maybe she could have lived if someone had seen her earlier."
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