The idea of introducing vertical sensor beams in lifts, as suggested by Mr Aaron Ang Chin Guan ("Consider lift sensors that can detect thin items"; Forum Online, Nov 11), looks good, but I doubt that they will work better than the horizontal beams over a period of time.

Foreign particles such as litter, dust and dirt may accumulate on the surface of the bottom sensor over time, hence affecting its sensitivity.

Maintenance activities like the mopping of lift floors and washing of lift lobbies may hasten such an occurrence.

I agree that even with the newer safety technology in place, accidents can still happen, as it is hard to predict when things will break down ("Experts weigh in on preventing accidents"; Nov 7). The onus is still on individual safety consciousness.

Perhaps, the authorities could post notes on the dos and don'ts of using lifts, to educate and enhance the public's safety knowledge.

The lift incident in Tah Ching Road was unfortunate and one that no one expected. We should learn from the episode.

Chee Chi Weng