If a building almost collapses in Davis Square and there’s no hipster with an adorable waxed mustache wearing jorts and a neon T-shirt promoting kale consumption around to bike passed it on a fixed gear, did it happen? The answer is yes.

Portions of Somerville’s congested crossroads have been closed down after construction at the old Social Security office at 240 Elm St. was deemed unsafe because of a wall that is not attached to the roof framing and is structurally compromised. Until the proper shoring is installed, the wall could collapse at any point, authorities said.

“We did not authorize for masonry removal to proceed on this side of the building prior to shoring and feel that it currently presents a dangerous condition,” Roome and Guarracino LLC Structural Engineer Jason Ferris said in a press release. “Along this wall, between the steel beam bearing piers, the masonry has been taken down below the roof framing level and no longer engages the wall with the roof diaphragm.  Not only does this result in an unstable wall condition, it also results in weakening the stabilization of the piers supporting the steel girders.”

Engineers from Roome and Guarracino LLC, hired by the building owner, found that three tower legs on the first floor of the construction project were missing. Without those lower legs, the weight of the building can’t be properly dispersed and make its way down to the foundation. 

The city closed off Elm Street between Dover and Russell streets, keeping cars and pedestrians off of Chester and Grove streets until further notice.

This closure means no access to Meju, Julie’s Nails and the Burren’s patio on Elm Street as well as the sidewalk on Chester Street from Diva to Red Bones. It also means the Dunkin Donuts in the first floor of the building will be closed.

The city posted information on detours established on Tuesday aimed to accommodate morning rush hour commutes:

- Highland Ave. between College Ave. and Grove St. will be temporarily converted to accommodate two-way traffic.

- Vehicles traveling east on Holland St. may take a right onto Dover St., or continue onto Highland Ave.

- Vehicles traveling west on Highland Ave. may continue onto Holland St., or right onto College Ave. Cars will not be permitted to turn left onto Dover St.

- Vehicles traveling into Davis Sq. on College Ave. may only right onto Holland St. Cars will not be permitted to travel straight onto Dover St. nor take a left turn onto Highland Ave. Somerville Police will direct traffic in the areas affected by this shutdown and message boards will be set up in Teele Square and the Powder House Rotary warning commuters of the traffic changes.

T buses that normally stop at Elm Street and Chester Street, Routes 87, 88, 89, 90, 94, and 96, will pick up and drop off in front of the Citizens Bank building at 212 Elm St.