The sentences were passed by the court of Special Judge Devendra Singh Solanki here.
On August 21, 2011, the three accused - private bus conductor Dilip Sharma, its driver Tarun Soni and cleaner Rajkumar Kushwaha - had an argument with the driver of another bus over passengers at Balsamad barrier in Barwani district.
Following the altercation, the trio locked the door of the other bus and set it on fire, which saw 15 passengers being charred to death while 19 others were seriously injured.
The court has directed that compensation of Rs 3 lakh each be paid to the kin of those killed in the incident while injured persons are to receive Rs 50,000 each out of the fine collected from the bus owner.