Buildings almost never fall down without telling you first. In the days or hours beforehand there is usually a crack that was not there last week, a door that suddenly will not close, or a sound from a wall that has no reason to make a sound. The tragedy of most collapses is not that the warning was missing — it is that somebody saw it and decided it could wait.
This guide sets out the signs that matter, the ones that usually do not, and what to actually do when you see them.
The warning most often ignored
On 23 April 2013, cracks were found in the pillars of Rana Plaza, an eight-storey building near Dhaka housing several garment factories. An engineer inspected it and said the building was unsafe. The shops and the bank on the lower floors closed. The garment workers were told to come back the next morning anyway.
The building came down the following day, killing 1,134 people. It remains the deadliest structural failure of the modern era, and the warning arrived a full day in advance. You can read the full record on our Rana Plaza page.
That pattern — a visible sign, a judgement call, a decision to carry on — repeats in a large share of the collapses we record.
Signs that need action today
Not every crack is dangerous. These are the ones that change the answer:
- Diagonal cracks near the corners of doors or windows, especially if they run through the wall rather than just the plaster. A crack you can slide a coin into is a different problem from a hairline one.
- Cracks in columns or beams, not just walls. A column is holding the building up; a partition wall is not. Horizontal cracking around a column, or concrete flaking away to expose the steel inside, is the most serious sign on this list.
- A door or window that has stopped closing when nothing was changed. Frames go out of square when the structure around them moves.
- Floors that have started to slope, or a gap opening between the floor and the skirting.
- Rust stains bleeding through concrete. Steel reinforcement expands as it corrodes and pushes the concrete off from the inside.
- Sagging in a ceiling or roof slab, or a visible dip along a beam.
- New sounds — creaking, cracking or popping from walls, particularly at night when the building is quiet.
- Water pooling against the foundation for days, or soil that has washed away from around the base.
One of these on its own may have a dull explanation. Two or three together, or any one of them getting worse week by week, is a building that needs a structural engineer rather than a painter.
Signs that usually are not urgent
It helps to know what not to panic about, because false alarms are how real warnings get dismissed later:
- Fine hairline cracks in plaster in a new building. Fresh plaster and concrete shrink as they cure, and this is expected in the first year or two.
- Vertical cracks along the join between two different materials, such as where a brick wall meets a concrete column. Materials expand at different rates.
- Small cracks that have not changed in years. Movement that stopped is far less worrying than movement that is continuing.
A simple way to tell the difference: mark each end of a crack with a pencil and write the date. If the crack grows past the marks over the following weeks, it is live.
When collapses become more likely
Structural failures cluster around a few conditions, and knowing them tells you when to look harder:
Heavy or prolonged rain
Water is the most common accomplice. It saturates the ground and weakens what the foundation is standing on, it adds weight to flat roofs that are not draining, and it seeps into masonry and corrodes the steel inside. Older buildings and unreinforced brick walls are the first to go. In South Asia this is why the monsoon months carry a visible rise in wall and roof collapses — see the live picture for Pakistan or any other country page.
After an earthquake — including small ones
A building can survive a tremor and still be left weaker than it was. Damage inside a column is not always visible from the street. Collapses in the days and weeks after a quake, sometimes triggered by a much smaller aftershock, are common enough that engineers treat post-earthquake inspection as routine. Our earthquake tracker shows where those aftershock sequences are running.
During construction, demolition or renovation
A large share of the collapses we record happen while work is going on: extra floors added beyond what the original design allowed, a load-bearing wall removed to open up a room, formwork struck before the concrete has gained strength, or excavation next door undermining an existing foundation.
Buildings carrying more than they were built for
Residential blocks converted into warehouses, machinery installed on upper floors, water tanks added to roofs. Rana Plaza had been built as a commercial building and later carried heavy industrial generators on floors that were never designed for them.
What to do when you see a warning sign
- Get people out first, ask questions second. Evacuation costs a day of work. The alternative does not have a price.
- Do not let anyone back in to fetch belongings. Most deaths in partial collapses are among people who returned.
- Photograph everything, with the date. It establishes how fast the problem is moving, and it matters later for insurance and liability.
- Call a qualified structural engineer, not a contractor who would like the repair work. In many countries the municipal or district building authority can order an inspection.
- Tell the neighbours. A failing building rarely falls straight down; adjoining structures are at risk too.
- Do not accept a cosmetic fix. Filling a structural crack with plaster hides the only evidence you had.
How we track building collapses
Building collapses are one of the categories with no official global feed. There is no worldwide agency publishing a machine-readable list of them the way seismic networks publish earthquakes. They surface almost entirely through local news reporting, often in the local language and often only in the regional press.
That is the gap this site was built to close. We read local media across dozens of countries in their own languages, classify the reports, and place them on a map, so that a wall collapse in a district town appears in the same record as a major structural failure in a capital city. Every one gets a permanent page with its location, severity and source.
You can see the running picture on the building collapse tracker, browse everything recorded in the last 24 hours on today's page, or look up your own area from the city index.
Two things you can do that make the record better:
- Report an incident you know about. Local knowledge reaches us long before the news does, and every submission is reviewed before it is published.
- Set up free alerts for your country, so a severe incident near you arrives by email rather than being something you find out about afterwards.
The short version
Cracks through columns, doors that stopped closing, floors that slope, rust bleeding through concrete, and new sounds in the walls are the signs worth acting on — particularly after heavy rain, after an earthquake, or while building work is going on. Mark the cracks and date them. Get people out before you get an opinion.
Buildings give warnings. The record is mostly made up of the times nobody acted on them.
