A 200-kg iron beam came off the 13th floor of an under-construction building in Kanjurmarg on September 18, landing on a tree and the tin roof of a police office right next door. Nobody was hurt. It could easily have gone the other way.

The site belongs to KAMS Realtor, and it sits beside the externment department office of Kanjurmarg police station. Assistant Police Sub-Inspector Vishwas Dashrath Desai, 56, was on day duty and working at his computer around noon when he heard the crash. He stepped outside to find the beam lying right in front of the entrance.

Workers at the site reportedly confirmed to police that the beam had come from their building.

This wasn't the first warning sign. Police say stones, gravel and iron rods had fallen from the same site near the office on more than one earlier occasion, and that the contractor had already been cautioned about it. This time it was a beam heavy enough to do real damage, and it did, tearing into the tin roofing of the office.

Mumbai police have registered an FIR against the site contractor, Mitesh Jain, site engineer Dhanraj Ramchandra Jagtap, and safety supervisors Vikram and Sohel Mirza. The case has been filed under provisions of the Bharatiya Nyaya Sanhita relating to acts that endanger the life and personal safety of others.

None of the four has been convicted of anything. An FIR is the start of a process, not the end of one, and investigators are still working out exactly how a beam that size ended up going through open air rather than staying bolted in place thirteen floors up.

What happens next depends on that investigation. Police will need to establish whether the earlier warnings about falling debris were ignored outright or whether this was a separate failure altogether, a loose beam rather than loose stones. Either way, an office that people work in every day sat directly in the blast radius of a construction site that had already been flagged as a hazard.

For now, the tin roof is damaged, the tree took the worst of the impact, and Kanjurmarg police say the probe continues. The bigger question, one Mumbai's construction sector keeps circling back to after every near-miss like this, is what it actually takes for a warning to stop a site instead of just sitting in a file somewhere.