Aside from a few small flare-ups, the fire was all but over inside the Luongo Restaurant in East Boston on Nov. 15, 1942. And then, at 4:15 a.m., a massive wall tumbled down, causing the building to collapse and trapping dozens of firefighters under heavy debris.

Six firefighters lost their lives 70 years ago Thursday. The incident gripped the city until it was overshadowed by a far-deadlier tragedy 13 days later, the Cocoanut Grove Nightclub fire that killed 492 people.