So city dwellers reshaped the fire escape, and in so doing it changed urban life. Fire escapes became makeshift jungle gyms for kids and offered a place to catch a breeze while hanging the wash to dry. Today it’s uncommon to hear of people dying after rolling off of a fire escape in their sleep, but it’s normal (if still illegal) to see fire escapes turned into vegetable gardens, smoking patios, and makeshift bike racks.

Repurposing fire escapes is one timeless tradition associated with these architectural structures. Another ritual: drawing the ire of landlords. When the 1901 restrictions required that fire escapes become larger, they had to cover more of a building’s facade as a result. This created even more space for tenants to expand, while building owners worried that the fire escapes would reduce the value of their investments.

Yet with new fire escapes climbing up buildings like invasive ivy, it was some consolation to know that they would be a shared inconvenience. Hotels, factories, and schools also found themselves looped into the fire-safety trend, although hotels fought determinedly to shield their guests from what they argued were vacation-ruining additions. What guest, proprietors reasoned, would stay in a hotel that constantly reminded them of a potential catastrophe? Their initial solution—more of the cleverly hidden ropes—didn’t work well for anyone, let alone ladies in long skirts. Eventually hoteliers were forced to adopt the metal structures. There is little evidence that any subsequent vacations were ruined.

Despite their claims to safety, even these heavy metal fire escapes failed quite frequently. A famous fire-escape disaster, the Triangle Shirtwaist Factory fire, took place at the Asch Building in Greenwich Village. On March 25, 1911, 146 workers, mostly women, were trapped by fire and died. The doors were locked, and the stairs were inaccessible, but a fire escape was present and should have provided egress for the workers. But it was so flimsy that the panicked workers who were able to reach it overloaded the structure. It peeled off from the building, trapping those above and sending the workers who had reached it plummeting toward the street.

There have always been questions about how much urban dwellers can trust external fire escapes. A New York Times editorial published on March 21, 1899, worried that they offered “little or nothing” in the way of precaution. “A burning tinderbox is no safer for being [enclosed] in a cage of red-hot ladders,” the editorial continued. By 1930, fire escapes were still being constructed, but few people saw them as safety devices first. They had become architectural accessories that might be repurposed for escape, not the other way around.

Even so, for nearly a century the exterior fire escape persisted as the preeminent mode of fire safety for mid-rise buildings in American cities, especially the nation’s oldest, like New York and Philadelphia. But few pedestrians today may realize that much of the iron and steel that hangs above their heads on city streets is often original. A 1968 change in New York building codes banned the construction of external fire escapes on almost all new buildings. What is there now has been there for a long time. The metal vines have seen the city grow, seen it change, and they have played an integral role in its evolution. The seeds of contemporary New York germinated on fire-escape balconies and grew below their entwining shadows.