Swastik Banerjee. (Sanjoy Chattopadhyaya)

A Class XII student of Delhi Public School, Ruby Park, fell to his death from the top floor of the Mani Square mall on Tuesday afternoon with CCTV cameras capturing snatches of the fatal drop from five levels above the ground.

Camera footage made available to police also shows 18-year-old Swastik Banerjee, described as “a straightforward and optimistic guy” on a social networking site, entering the Bypass mall alone with a backpack on his shoulders a little after 2pm.

The suspected suicide occurred between 2.20 and 2.25pm with no witness except a guard who heard a thud — it was Swastik’s backpack — and looked up to see the boy crashing into the concrete driveway just below the footbridge that connects the fourth-floor car park with an Ezone showroom in the main building.

Police found a phone number scribbled in bold on a diary inside his backpack and dialled it to discover that it belonged to his father Supriyo Banerjee, a senior official of Bharat Heavy Electricals Ltd. Supriyo told the cops that his son had left their Lake Gardens home around 10am without specifying where he was going. He became incommunicado after that.

Swastik’s parents — mother Swarnali is a schoolteacher — made several attempts to contact him from noon but found his cellphone switched off. Investigators found a chemistry textbook along with the diary and some other belongings in the boy’s backpack but couldn’t locate his cellphone.

“Everything points to suicide as of now. Why an 18-year-old with a positive outlook to life would take recourse to such a drastic step remains to be known,” said an investigator.

Swastik, who his teachers at DPS said was one of the top 10 students of the Class XII science stream, had written his pre-board math exam on Monday but wasn’t very happy with how it went, a police officer quoted his father as saying.

So do his parents think exam anxiety was the possible trigger for suicide? “The reason isn’t clear. No exam was scheduled for Tuesday and he was not supposed to go for any private tuition either. So why he stepped out of home and went to the Bypass mall is still a mystery,” the officer said.

The police also aren’t sure whether Swastik fell from the footbridge or the car park. “From what we have gathered, he walked towards the car park through the electronics showroom,” said a mall employee who didn’t wish to be named.

There weren’t many people at the mall on a weekday afternoon when the incident occurred.

A spokesperson for Mani Square, a popular haunt of youngsters like Swastik, said the mall administration reported the incident to the police within minutes of being informed about it.

A team from Phoolbagan police station reached the mall and removed the body.

Swastik’s death has left the authorities of DPS, Ruby Park, and his schoolmates in shock. “He was confident of scoring above 85 per cent in the board exam. I don’t believe this,” cried a classmate.

Principal A. Ghosh said Swastik was a “good boy” who also did well in studies. “This is very unfortunate,” Ghosh added.

The chemistry exam slated for Wednesday has been cancelled.

Swastik had written on the social networking site Orkut that the first thing to notice about him was his smile. He also mentioned his fondness for gaming, action movies and the Harry Potter series.