The guard of Turna Nishita train said foggy weather and failure of emergency brake led to early Tuesday's fatal accident that left 16 people dead.
"At first, we did not see the signal. When we saw it, we pushed the emergency brake but it did not work. Also, it was difficult to see the signal as the track is not straight," said guard Abdur Rahman.
"There were some stockpiles of bricks in the railway station and we could not see the signal clearly. The foggy weather also obstructed our view," he said.
However, Udayan Express assistant driver Abdul Qaiyum Bhuiyan told The Business Standard that the Turna Nishita driver did not obey the signal.
"Our signal was clear. As we were entering the station, our 10th coach was hit. Of the 16 coaches, number 10, 11, 12 and 13 were badly damaged," he said.
Turna Nishita hit Udayan Express when the latter was entering Mandabagh Railway Station.
Rahman said Turna Nishita driver Taser Uddin sustained injuries in the accident and was admitted to a local hospital in Brahmanbaria.
The train's assistant driver Apu Dey could not be reached for comment.
Udayan Express reached Chattogram at 11:30am on Tuesday. Its driver Sanaul Tipu told The Business Standard the train reached Chattogram with nine coaches after the accident.
He also echoed Qaiyum's comment, saying the Turna Nishita driver did not follow the signal.
The two Turna Nishita drivers drove Mohanagar Provati from Dhaka to Chattogram on Monday. Mohanagar Provati left Dhaka at 7:45am and reached Chattogram at 3:50pm. After a seven-hour break, they again started an almost eight-hour journey, driving Turna Nishita to Dhaka.
It is often alleged that train drivers do not get enough rest between trips. This leaves them exhausted and increases the chance of accident. The probe report on the oil wagon's derailment in Chattogram in April this year said lack of proper rest led to the accident.