The Engineering Institute of Thailand (EIT) has said a broken suitcase wheel might have caused an accident which resulted in a woman losing part of her leg after falling on one of Don Mueang airport's moving walkways.
Boonpong Kijwatanachai of the EIT on Friday said they assumed the luggage wheel may have been stuck and broke the travellator's comb, which then fell under the platform and pried the platform open wide enough for the woman's leg to fall in.
However, investigations into the accident are ongoing, he said.
Mr Boonpong said maintenance workers had been testing the system daily before the system was operated.
The EIT is urging people to be careful and avoid using a mobile phone while using both a walkway and an escalator, he said.
Travellators are designed for flat surface use and can hold a total weight of 160 kilogrammes per panel, while an escalator can hold a weight of 75kg per panel, he added.
The injured woman is being treated in an ICU room at Bumrungrad International Hospital, police said.
A son of the injured woman said via Facebook that he was concerned about his mother's mental condition as she could not imagine living with only one leg.
He thanked those people who expressed their concern over his mother's well-being.
A team of psychiatrists are helping his mother, he said.