LUCKNOW, May 16 -- Preliminary investigation into the sleeper bus fire that killed five people in Lucknow on Thursday point to a combination of causes that worsened the tragedy-suspected electrical short circuit, illegal gas cylinders on board, and overcrowding beyond the bus's permitted capacity. Police and fire officials said the fire started around 4:40 am when the Delhi-bound private bus from Bihar's Begusarai was near Kate Bhit village on the Lucknow Outer Ring Road near Kisan Path. While initial reports suggest a short circuit as the trigger, fire personnel responding to the emergency noted multiple loud explosions. "These were likely caused by small gas cylinders and air-conditioner compressors," said Mamchand Bargujar, fire station officer, PGI, in an official statement. According to eyewitnesses, the bus continued moving even after catching fire, spreading panic among passengers. Witnesses said the driver and conductor smashed a window to flee, leaving those inside to scramble for safety on their own. According to deputy commissioner of police (South), Nipun Agarwal, some passengers were reportedly carrying small LPG cylinders used for cooking during long journeys. These cylinders appear to have intensified the flames, resulting in rapid spread and explosions inside the vehicle. "When fire crews from Lucknow and Barabanki reached the spot at 5:02 am, they were met with a large fire and intermittent blasts," Bargujar said. The bus, with registration number UP17 AT 6372, left Begusarai at 12:30 pm on Wednesday and picked up more passengers in Gorakhpur around midnight. By the time it reached Lucknow, it was carrying 80 passengers, exceeding the approved capacity of 60. An FIR filed by one of the passengers mentions the bus was overfilled. Officials said the bus had an extra detachable seat installed near the driver's cabin. This blocked the gallery, reducing the space available for escape and causing a bottleneck when the fire broke out. The main exit jammed due to the fire, and the emergency gate reportedly failed to open. The layout left many with no safe exit.A survivor, Ravi Kumar, said, "A man climbed over me and ran away. I somehow survived. Many got stuck while trying to escape. Those who fell were unable to get up. People trampled over them trying to save themselves. Most of our belongings were destroyed in the fire." Another passenger, Tara Chand, said, "We all woke up to the smell of smoke. The driver and conductor escaped without informing anyone."...