Tasmir died around 9.50pm after undergoing treatment at Chittagong Medical College and Hospital (CMCH) for the last eight days, said Harun Or Rashid, a physician at the Intensive Care Unit (ICU) of CMCH.
He added, Tasmir was being treated at the ICU as he had suffered severe head and neck injuries in the accident.
Earlier on Friday, another victim Ayat Hossain succumbed to his injuries while undergoing treatment at the same hospital.
On 29 July, eleven people, all aged between 20 and 30, died when a speeding express train hit the microbus carrying them at a level crossing in Mirsharai.
Seven of them were SSC and HSC examinees, while three of them were young teachers from a coaching centre named ‘R and J Private Care’ and the other was the microbus driver.
They were returning home in Hathazari upazila after a tour to the Khoiyachora Waterfall in the hills of Mirsharai.
The Chattogram-bound Mahanagar Provati express from Dhaka ploughed through the microbus, dragging it around a kilometre down the railway track.