The China Mail report on 12 March 1918 of the fifth day of the Inquiry into the Happy Valley Racecourse Fire Disaster includes the testimonies of the Unity Stand holders, John Johnston Blake and my grandmother, Hannah Warren's half brother, John Olson jnr., who were present at the collapse of the sheds. John Olson, in the midst of the collapse, helped to shepherd people out. The Unity Stand consisted of matsheds 4, 5 and 6, part-owned by my grandfather C.E. Warren in conjunction with Blake and Olson. The excellent online article of Dr Roy Xavier on the subject of the fire has already been cited on Gwulo. I'd also like to commend his expanded version with 70 footnotes: Roy Eric Xavier, ‘Death at the Races: the Portuguese presence during the Happy Valley Fire of 1918,’ in Journal of the Royal Asiatic Society, Hong Kong Branch, Vol. 53, 2013, pp. 89-107. It is also online in his "Articles" section. The posted image is taken from a bound copy of the China Mail, in which some of the text has unfortunately disappeared into the spine. It may be possible to get a more complete image from the old HK newspapers site.