A mayday call during an early‑morning house fire in D.C. led to tense moments for firefighters Sunday after part of the home collapsed, authorities said.

D.C. Fire and EMS responded to the 3400 block of 24th Street SE near Southern Avenue just before 1 a.m. It said crews arrived to find heavy fire through a two‑story home.

Flames also spread to the attic of the adjacent attached home.

A rear porch collapse triggered a mayday call, prompting a rapid‑intervention response on the scene.

A second‑alarm assignment was also dispatched, bringing roughly 100 firefighters to the incident.

Two firefighters were injured, including one seriously. D.C. Fire and EMS spokesman Vito Maggiolo said both first responders were transported for medical care.

No civilians were hurt, but residents from the two homes were displaced.

Maggiolo said the cause of the fire remains under investigation.

A map of where the fire happened is below: