It took Mr Harun Rashid and a team of 10 cleaners almost three hours to wash the blood off the walls and floors of the block yesterday.
And the 29-year-old Bangladeshi national still cannot understand what caused the "river of blood" at Block 505 Tampines Central 1, most of which was pooled at one of the staircase landings between the eighth and ninth storeys of the HDB block.
Mr Harun, at the time, was unaware of the drama that had taken place in the early hours of yesterday morning.
A commotion had broken out at the staircase landing between a 37-year-old Chinese national and the police, who later arrested him for the alleged murder of his housemate.
The body of a woman, also a Chinese national, had been found by the police at a rental flat at nearby Block 503 at 11.43pm on Tuesday.
The woman was pronounced dead at 12.10am.
According to eyewitnesses, the man had fled from the scene to Block 505, where he was arrested, but not before the commotion that lasted a couple of hours.
The New Paper understands the man was standing on a ledge outside the staircase landing, clinging to the parapet.
Residents living on the eighth storey of the block said they were stunned when they heard loud noises coming from outside their flats around midnight.
One of them, who wanted to be known only as Mr Ng, in his 60s, said: "I heard people shouting, 'Open your eyes, open your eyes!' and 'We're here to help you'."
A neighbour, Madam Lim Ai Lee, 41, a teacher whose unit is next to the staircase landing, added: "I thought at first that it was a quarrel because there have been cases of people quarrelling and shouting in our area before.
"But the voices, which sounded like four to five different ones, kept getting louder and louder.
"So I shouted at them to quieten down and I even called the police, but I didn't dare go out and interfere because the voices sounded very tense. The noise only died down at about 3am."
None of the residents TNP spoke to actually saw what happened, but the amount of blood at the scene shocked them.
Said Madam Lim to The Straits Times: "I thought it was red paint from construction work. There was so much. Who would have thought it was blood?"
Mr Harun, who has worked in Singapore for eight years, added: "I've never seen so much blood in my life before.
"While I was washing I kept wondering what must have happened to have a river of blood dripping down the walls of the block. The blood flowed down three floors," he said.
"When I first saw it, I was shocked and scared," he said.
Mr Harun used a high-powered hose to clean the blood before some of his colleagues painted over the walls.
"I just hope whoever the blood came from is okay," he said.
It is unclear whether the man and the woman, who was killed, were married or dating.
TNP understands that the suspect, who sustained injuries and was bleeding profusely, fled to the neighbouring block about 20 metres away, before the police spotted him.
The Singapore Civil Defence Force (SCDF) confirmed in a statement that "an airbag was deployed" at the foot of the block after it "dispatched two fire engines, two special vehicles and an ambulance to Block 505".
It said the suspect was "eventually pulled to safety by SCDF personnel and policemen before the conscious but drowsy man was taken to Changi General Hospital".
The police declined to reveal if weapons were found at the rental flat where the woman was discovered.
When TNP visited the crime scene, eight other people who were in the flat during the time of the murder, were seen outside the five-bedroom flat giving officers their personal details and answering questions.
The police said investigations are ongoing.
This article was first published on December 18, 2014.
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