Nairobi, Kenya -- Attempts to retrieve a woman's cell-phone from a pit latrine ended in tragedy, with three men dying from suffocation, one by one.

The phone, belonging to Kenyatta University student Dora Mwabela, slipped into the pit as she answered a call of nature.

Anxious to recover her Sh6,000 Alcatel phone, Dora offered Sh1,000 to anyone who would recover it.

First to try was radio technician Patrick Luhakha, aged 30, who was recently married.

Along with others he ripped up the toilet floor at the house in Kisumu Dogo, in sprawling Kongowea, Mombasa, before plunging a ladder down into the pit and beginning his descent.

In spite of calls for him to come up, Mr Luhakha failed to resurface.

Another neighbour, water vendor Kevin Wambua, quickly climbed down the ladder to check on his friend. But he slipped and fell – and he too was unable to get out.

Then a third man, neighbour John Solo, went down to try to rescue them both in the presence of policemen.

But he was overcome by strong fumes and collapsed when only halfway down the ladder.

He was hauled to the surface by yet more neighbours who rushed him to hospital but he was found to be dead when still on the way.

A fourth would-be rescuer had to be held back by Acting Mombasa police boss Peter Njenga after he defied advice and insisted on going down the pit to help his friends.

"We would have been talking of four dead," said Mr Njenga.

"The fumes inside must be extremely poisonous considering the short time it was taking to disable the retrievers."

Neighbours and onlookers at the house, built in 1976, were still trying to come to terms with the tragedy yesterday.

Mrs. Godliver Auma, a sister of the first man to die, Mr Luhakha, said he had gone to visit his elder brother from his work place but was first to respond to the student's call for help.

The bodies of the three men were later retrieved and taken to Coast Provincial General Hospital.

The cell phone was not found.

A concentration of ammonia, which comes from human waste, makes the depth of pit-latrines extremely dangerous.