Investigators of a fire that killed three New Zealand triplets and 16 others in Doha last month say there was a "lack of adherence to laws, systems, and measures by all concerned parties".
The investigation found the fire was caused by faulty electrical wiring in a fluorescent light in a Nike store in the Villaggio Mall.
The store was next door to the Gympanzee nursery, where 13 children including two-year-old New Zealand triplets Lillie, Jackson and Willsher Weekes were.
The triplets' grandfather Ron Turner said he did not wish to make comment because it was only an interim report and the family were still waiting for more information.
An investigation committee has found the fire was not premeditated, but that the plastic components of the light caught on fire.
The components then fell down onto items in the store, which were made from flammable materials, spreading smoke throughout the mall.
Emergency service workers arrived at the scene within minutes but weren't aware children were trapped inside the building until 30 minutes later, the committee said.
There was also a lack of response from the mall's security and from staff at the sports store. The nursery was not licensed by the ministry of social affairs and did not meet safety conditions, the investigating committee found.
There were no plans in place at the mall to "prevent, contain or at least reduce the effects of such an incident".
There was a general "lack of adherence to laws, systems, and measures by all concerned parties to different degrees," the committee said. "This includes adherence to design, licence and safety conditions, which contributed to the Villaggio catastrophe".
It recommended 11 changes to the mall and its safety procedures, including a review of regulations governing the activities of baby care facilities.
The Heir Apparent Sheikh Tamim bin Hamad Al-Thani has ordered that the recommendations are referred to the Cabinet and that the Cabinet implement them as soon as possible.
The committee's chairman had reportedly visited the families of all those killed to tell them about the report.
All 19 people killed in the fire on May 28 were foreigners, including the three New Zealand toddlers.
New Zealand couple Martin and Jane Weekes had come home to have their children, but were living in Doha at the time of the fire.
The parents described their children as "three special yet very different little people" at their funeral last week.
How the events unfolded, according to the investigating committee
Villaggio, Doha, May 28:
* A light fixture in the Nike store catches on fire, and its plastic components fall onto flammable items below.
* Nike staff and security fail to extinguish the fire.
* The first recording of smoke was at 10.50am.
* Smoke quickly spreads to the Gympanzee child care centre next to the sports store.
* Civil Defence is informed about the fire at 11.02am.
* Civil Defence arrives at the Villaggio mall at 11.05am, but only discovers children were trapped half an hour later.
* A search and rescue team from the Internal Security Force tries to access the daycare centre, and removes the first trapped person at 12.50pm.
* Thirteen children, four teachers and two fire fighters died by smoke inhalation.