I was very concerned when I read the Singapore Civil Defence Force's letter, which stated that "HDB point blocks require only a single exit staircase for the evacuation of residents because there is not a large number of units on each floor" (Strong fire safety rules, enforcement in place; June 26).

The rule does not seem to apply to private apartments that are built like HDB point blocks - having four units on every floor. Such private apartments are required by the building code to have two staircases.

What alternative escape route is there for HDB point block residents if the only exit staircase is blocked by fire?

Some of our newer HDB point blocks are as high as 25 storeys. That means about 100 families' lives could be at stake, should fire break out at the only exit staircase.

Tan Yee Nee (Madam)