Crews continued their search Saturday for two missing ironworkers trapped in the rubble of a Grays Ferry parking garage that collapsed earlier this week.

Philadelphia’s Ironworkers Union Local 401 identified the men as Matthew Kane and Mark Scott Jr. early Saturday in a social media post, which has since been edited to omit the names. Another man, who was pulled from the debris and died at a hospital, was identified as Stepan Shevchuk. All three were members of the union.

A spokesperson for the Philadelphia Department of Public Health — which houses the Medical Examiner’s Office — did not immediately respond to an email seeking more information.

The seven-level structure under construction at 30th Street and Grays Ferry Avenue collapsed Wednesday about 2:15 p.m., when a precast concrete roof segment “failed” and fell, echoing like a crack of thunder.

“This unthinkable tragedy has devastated our local union and the families of both the victims and survivors,“ the post reads. ”We’ve lost three loved and respected members of our 401 family and wait in anticipation to bring our Brothers home.”

The post came as crews began demolishing what’s left of the Children’s Hospital of Philadelphia’s garage, which is extremely weakened and “could collapse at any moment,” officials have said. The building’s unstable condition has forced rescuers to proceed slowly and carefully, even as the two workers remain unaccounted for.

But early Saturday morning — after a day of preparations — a wrecking ball began swinging at the seven-level structure, sending dust flying and chipping away chunks of what was once meant to be the roof of the CHOP garage. By noon, the first slabs of concrete fell.

Tara Furrule, 39, and her fiancé Mitchell St. Louis, 37, were on their morning coffee run when they passed by the garage to pray.

“It is an overwhelming tragedy and the loss of lives makes it even more unsettling,” Furrule said. “The workers dying is crazy; it’s hard not to think about them. I’m at a loss for words.”

For St. Louis, the pain is deeper. As a residential project manager, he has construction workers under his charge: “I think about my people, their safety is number one … and what I have to do to make sure every one of my guys out there is going to make it home everyday.”

Meanwhile, Mayor Cherelle L. Parker was holding a community meeting at Vare Recreation Center in South Philadelphia.

“The work to bring this structure down safely has already begun,” the mayor said. “This marks a critical transition … from response to recovery. Our priority remains unchanged — to recover the missing individuals with the greatest amount of dignity and respect humanly possible.“

» READ MORE: Crews begin demolition of collapsed Grays Ferry garage

It’s unclear how long the deconstruction may take, and officials have been reluctant to give a timeline as the structure’s stability must be continually reevaluated.

Precast concrete is a common construction material — especially in parking garages and bridges — that is poured off-site, and then its slabs are fit together. While accidents are rare, they can be deadly because of the material’s sheer weight.

Parker has promised a thorough investigation into what caused the garage to collapse, and the district attorney’s office was at the site ensuring any evidence was preserved.

This is a developing story that will be updated.