WARNING! Danger for Bus Passengers at the Singapore CIQ

Thousands of bus passengers use the Woodlands CIQ on the way to Johor.
This is what happened to one passenger yesterday.
I was on my way back to JB and had disembarked from the Johor-Singapore Express at about 11:15am.
There is a wide covered walkway for bus passengers leading to the escalators for Immigration clearance. Across the walkway is a small drain maybe 35mm deep and 60mm wide and this is covered with a perforated metal grating in sections about 70cm long just resting on the drain.
Yesterday I stepped on a cover, most likely at the end and the section lifted slightly causing an elderly lady to trip. I had already stepped off the cover but I heard the sound and just saw her falling forward.
Luckily she managed to use her arm to prevent her head from striking the ground but her spectacles flew off.
A few fellow passengers helped her get on her feet and fortunately she was not badly hurt and her specs were not damaged in the fall. I am sure she is feeling sore today. The plucky lady reassured us she was OK and thanked us for helping her and I apologised to her for the accident.
A duty policeman was approached and told of the incident. He advised that the danger of the gratings had already been reported and advised me to write an official complaint.
I would have expected that the officer in charge of public safety would have taken some safety measures to prevent a recurrence.
There are 2 ways to do this:
1.Remove the small drain completely with a small gradient on the floor to prevent ponding. This is the safest solution.
2.Secure each of the gratings with 2 conceaed/recessed rawl bolts.