Take a few steps into the deathtrap called Bhatdee -- a dark and dank underground mine in Jharkhand that swallowed 50 miners last week -- and claustrophobia sets in. You gasp for air. It is scary and depressing.

Yet, miners have been going into the tunnel of this obsolete mine for the last 60 years to bring out coal. Rescue experts now wonder how the mine was operational for so long without an accident taking place.

"The miners go down on one of the steepest gradients, where you cannot even stand properly, forget walking 70-80 feet deep into the mine," said an expert involved in the rescue work. Untrained individuals usually return after going in just 30-40 ft, while the shaft is almost a kilometer long.

The mine is 'primitive,' say experts. It is fully manual without a touch of modern technology, which made safety measures critical. However, even basic safety norms were not adhered to, according to a relative of Chandu Mahato, who died in the disaster.

"Most of them were not carrying a stand-by breathing apparatus. Besides, the sand filling in empty spaces was not proper," he said. Even the equipment to measure the density of methane gas in the mine shaft was inadequate, he added.

"We have a device to check the methane level, but it is not possible to check it in every corridor," said the director (technical) of Bharat Coking Coal, S N Katiyar, in charge of the rescue operations.

"A methane level of 5-14 cubic millimetre per tonne of coal is an explosive level. You just need a spark for an explosion," he said.

Bhatdee is a high-methane-level mine. Katiyar admitted that there was no fool-proof method to check accidents in such mines.

The Chairman and Managing Director of BCCL, Partho S Bhattacharya, conceded the possibility of lapses in safety procedures. "We have suspended five engineers," he said. Besides Bharat Coking Coal, teams from sister companies like Eastern Coalfields and Central Coalfields and even a small Tisco [Get Quote] team was involved in the rescue work.

Investigation into the accident will be delayed as the mine is still full of methane gas.

"Our priority will be to reduce the density of methane gas in the mine by infusing fresh air. Only after that could we start the investigation," he said.

Meanwhile, the company will soon start the disbursement of compensation, totalling about Rs 9-12 lakh per victim.