Source: The Great Interpretation of Dreams (Ibn Sirin)
The collapse of stairs in a dream indicates a decline in position or corruption in religion.
Source: Perfuming Humanity in the Expression of Dreams (Al-Nabulsi)
The collapse of stairs indicates the death of a servant or difficulty in travel.
Source: Signs in the Science of Expressions (Ibn Shaheen)
The collapse of stairs is interpreted as worry and calamity.