“Based on our investigations, we found no elements of foul play, sabotage or negligence,” Selangor police chief Hussein Omar Khan said at a press conference at the state government’s office here today.

Hussein said a special task force will be formed to decide who would be held responsible for the blaze as well as the next course of action.

The occupational safety and health department (DOSH), which led the technical investigation into the incident, said certain segments of the pipeline gave way because of cyclic loading and insufficient support from the ground underneath.

DOSH petroleum safety division director Husdin Che Amat said this was mainly caused by unstable ground conditions, leading to the physical failures at parts of the pipe, which then led to a gas leak and the blaze.

“The weak ground led to cyclic loading, which left stress lines and fatigue striations on the surface of the pipe. A metallography analysis showed that tensile overload was the main cause of the pipe’s failure.

“This damage slowly spread, causing ductile failure which led to the leakage of gas, triggering the fire.

“In summary, the pipe failed because the condition of the ground underneath was not strong enough to support the weight and pressure of the pipe,” he said.

The blaze on April 1 saw flames soaring over 30m high with temperatures reaching up to 1,000 degrees Celsius. There were no fatalities, but 150 victims had to seek treatment at hospitals.

It took firefighters nearly eight hours to extinguish the blaze, which left a 10m-deep crater, measuring 21m by 24m.

The fire destroyed 81 houses, with structural damage exceeding 40%. Another 81 houses were partially damaged, and 57 were affected but not burned.