A teenage boy suffered second-degree burns on his right thigh after sitting on what could have been acid at a bus stop in Bukit Batok.
When School of Science and Technology student Aung Phone Naing finally went to hospital, he was told he may have also suffered nerve damage. But tests failed to reveal what he sat on.
"I am confused that there is no answer. I'm worried that this would leave a mark on my leg," he told The Straits Times.
While waiting for a bus to take him to school on Wednesday morning, he decided to sit down as his schoolbag was heavy. Within a few seconds, he felt the right side of his pants getting wet. "I thought it was water, so I just wiped it away with my hand," said the bespectacled 14-year- old. "But my hand felt oily."
The Singapore permanent resident, who is from Myanmar, then glanced back at the metal seat of the bus stop along Bukit Batok East Avenue 3. He had not noticed the "transparent liquid" earlier, as the sky was still dark.
He took out his water bottle to wash his hands and sat at another seat. Then, he felt a tingling sensation on his right thigh. "I thought I was getting bitten by ants," he said, having noticed ants on the second seat.
After he boarded the bus, "the ant bites became worse", he said.
"I felt a scorching, burning sensation." He lifted his thigh, hoping the pain would subside. But it did not during the 30-minute ride to school.
As soon as he arrived, he went to the toilet and was horrified to see a black patch, about two palm sizes, on the back of his right thigh. "My skin looked burnt and felt harder than normal but it did not hurt," he said.
He called his mother, Madam Nilar Nwe, 44, and they headed for a nearby clinic. The doctor told them to go to the hospital immediately.
At the National University Hospital, the teenager was told there were two possibilities for the burn - oil that had become hot because of a lightning current through the metal seat, or a corrosive chemical.
He has also been told to rest at home, before going back to the doctor on Monday, when he will decide whether to do a skin graft, or let it grow back naturally.