Mamun was riding to Taratia Bazar from his Sardarpara village home in Jamalpur yesterday.
On the way, the teenager lost his life in a fatal accident.
When he reached near Polyakandi Bridge around 2pm, a wheel that came off an oncoming CNG-run auto-rickshaw hit his motorbike. He lost his control over the bike and fell onto the road.
Mamun, who was not using a helmet, died on the spot, said Dewanganj Police Station Officer-in-Charge Ashrafuzzaman, quoting family members.
Waj Karani alias Mamun, 16, son of Abdus Samad, was a tenth grader of Azizia Rose Bird Collegiate School in Dewanganj upazila.
Meanwhile, a college student was killed as a motorbike he was riding hit a power tiller in Junail Nayapara area of Madarganj upazila on Monday night, said OC Rafiqul Islam of Madarganj Police Station.
Nasim Ahmed, 18, son of Jaban Ali from Kukurmari village in the upazila, was a twelfth-grader at Krishi Bishwabidyalaya College in Mymensingh. His neighbours and co-riders -- Mahidul Pramanik, 16, and Manju Pramanik, 17 -- were injured and admitted to Madarganj Upazila Health Complex, said the OC.
In Sylhet, a mother and her son were killed and two of their relatives injured in a head-on collision between a truck and a CNG-run auto-rickshaw carrying them, on Shalutikor-Gowainghat road in Sotigram area of Gowainghat upazila yesterday.
Elora Parvin, 38, and Sajid Miah, 6, died on the spot, said police, adding that they were going to Jaflong.
The injured, Mahin and Sajib, were undergoing treatment at Gowainghat Upazila Health Complex. Police seized the truck but the driver fled.
[Our correspondents from Jamalpur and Sylhet contributed to the report]