Two weeks before she fell to her death, teenager Denyse Tan was behaving strangely.
She told her father, Mr Peter Tan, about hearing children crying and seeing a monster in her room.
He was so worried that he asked her if she was on drugs. When she said no, he believed her and did not pursue the matter.
A coroner's inquiry into the 18-year-old girl's death yesterday confirmed that she had been using drugs. State Coroner Marvin Bay said an analysis had detected methamphetamine, more commonly known as Ice, in her blood.
Miss Tan was found naked at the foot of Block 431, Bukit Panjang Ring Road, on Aug 19 last year.
The administrative worker, who is believed to have fallen from her seventh-storey flat, died in hospital about two weeks later.
Mr Tan, a 54-year-old divorcee, told The New Paper yesterday that his daughter had told him about seeing a monster in her room about two weeks before the tragedy.
"I was about to go to bed when she knocked on my door. She told me that she could hear kids crying in her room and that my girlfriend was a monster.
"She also asked, 'Daddy, what happens if one of these days I'm no longer here?'."
When the businessman heard this, he patted her a few times on her cheek to "wake her up" as she seemed groggy.
"She was mumbling and I asked her, 'Are you on drugs?' She immediately replied 'No'." Heaving a sigh, Mr Tan said: "I didn't know Denyse had been abusing drugs. I would have called the CNB (Central Narcotics Bureau) immediately if I had known that she had taken drugs.
"I would have done it out of love."
Yesterday, Coroner Bay found that her fall had occurred "in the wake of a likely drug-induced psychotic or delusional episode".
Recording a verdict of misadventure, he added that it was "likely to be accidental rather than a deliberate desire to harm herself".
The court heard that Miss Tan was introduced to drugs in 2012.
She knew then that one of her schoolmates was abusing cannabis and told him that she wanted to try some.
The schoolmate, who was not named in court documents, took her to a staircase landing near her home and passed her a joint, which she smoked.
IN JUNE 2013, SHE BOUGHT SOME CANNABIS FROM HIM IN SCHOOL DURING RECESS.
This was reportedly the only time she bought the drug from him, said Coroner Bay.
Despite her drug-taking, Mr Tan said Miss Tan performed well in school and even won an award for her academic performance on completing Secondary 5.
"But Denyse could be quite rebellious and I had gone to her school several times due to disciplinary problems.
"She picked up smoking in Secondary 2 and I advised her many times to quit. I knew she was mixing with bad company and told her many times not to mix with them."
After secondary school, she enrolled in the digital media course at Ngee Ann Polytechnic and maintained contact with the drug-peddling schoolmate through text messages.
Coroner Bay said: "The messages suggested to him that Miss Tan had started taking other drugs and at an ever increasing frequency.
"He also alluded to another occasion where she told him that she was high on 'Ice' after smoking it, and yet another occasion where she had advised him not to take 'Ice' as she was not able to quit the habit."
The court heard that Miss Tan dropped out of poly in June last year as she felt she was "not artistically inclined and might fail".
Mr Tan said she told him she wanted to enrol in another course - an advanced diploma of arts at a private school. "I didn't like her to drop out of poly but she told me she couldn't cope.
"I asked her if she wanted to work with me but she refused. However, she agreed to work in admin for my brother."
Mr Tan said he works from 7.30am to 11pm daily and Miss Tan had a bad habit of sneaking out of the flat which they share with his 24-year-old son. He spoke to her for the last time over the phone at around 7am on Aug 19 after noticing she was missing from her bedroom. She told him that she was at nearby Fajar Road having breakfast.
Court papers said Miss Tan had gone to visit a friend at around 2.30am and they chatted for hours before she left for home between 8.50am and 9.15am.
Mr Tan said his brother had also called her that morning and she said she was getting ready for work.
But one of Mr Tan's neighbours, Mr Lim Swee Long, later heard a loud sound outside his flat and when he looked out, Miss Tan was lying face down on a concrete walkway.
He called the police and Miss Tan was taken conscious to Khoo Teck Puat Hospital.
When police officers went up to the flat, they found her room disorganised. But there were no signs that a fight or struggle had taken place. The left-most window was open. The officers found a small plastic sachet of a brown grass-like substance, later confirmed to be cannabis. Mr Tan said he was at work when his son called about his daughter's fall.
"I was very shocked and almost fainted. I was in a daze and tried to make sense of what happened. I came home only after recollecting my thoughts."
According to court documents, he returned only at around 3pm and found a wet towel on his daughter's bed.
Miss Tan had a habit of coming out from the bathroom wrapped in a towel and would run quickly to her bedroom to get dressed.
Mr Tan went to the hospital later that day and saw her in the intensive care unit.
He said: "She couldn't talk and her eyes were closed. Over the next few days, she would squeeze my hand whenever I asked her questions.
"But her condition later got worse and she passed away two weeks later. I was with her when she breathed her last and I cried after finding out that she was gone.
Coroner Bay said Miss Tan's case was a reminder that the harm of drug abuse extends far beyond just the risk of overdose.
He added: "Drug users are likely to effect self-harm, or as in Miss Tan's case, place themselves in harm's way while in an intoxicated or even delusional state."
Nearly a year on, Mr Tan still could not hold back his tears when he talked about his daughter. Wiping his eyes, he said: "I wanted to give her a good life. Money was never an issue for her and we went on holidays every year.
"I still think of her almost every day."
CNB: Most young abusers are first-timers
There has been a rising, and worrying, trend of young people using drugs in Singapore.
Last year, 190 drug abusers below the age of 20 were arrested, compared to 181 in 2013.
Of the 190, a shocking 172 were new abusers, which made up 15 per cent of all new abusers caught last year.
The Central Narcotics Bureau (CNB) revealed this recently as part of its annual drug situation report.