The youth was identified as Shabbir Hossain Rafi, a grade 11 student of BAF Shaheen School and College.
Rafi was critically injured after falling from the roof of a three-storey building around 9.30 am on Monday, Gandaria Police Station OC Mohammad Saju Mia.
He was rushed to Dhaka Medical College Hospital where the on-duty doctor declared him dead.
Rafi, the son of the building's caretaker, lived on the ground floor with his family.
"Rafi went up to the roof while brushing his teeth in the morning. There were no railings on the roof and he some how fell from it," his uncle Jamal Sardar told reporters at DMCH.
Police have questioned several people at the building, said the OC.
"Rafi's parents scolded him on Sunday night for spending too much time on his mobile phone. We suspect he was upset by this and took his own life as a result."
But police are investigating the matter, said OC Saju.