A helper of a sand-carrying truck was killed as he fell under the wheels of his vehicle at Fiskar Ghat More on the Panchbibi-Kamdia Road in Panchbibi upazila of Joypurhat on Tuesday.The deceased was identified as Nayan Mia, 33, son of Chunu Mogla, a resident of Krisnapur village in the upazila.Officer-in-charge of Panchbibi Police Station Ashraful Islam said Nayan Mia died on the spot as he slipped off the tractor and fell under its wheels around 9 am.