Security camera footage captured the collapse of a two-story building in the District’s Trinidad neighborhood Wednesday, moments after two people crossed a nearby street and a firetruck returning from a call pulled up.

Video of the partial collapse of the building, a store at 1102 Staples St. NE that was being converted into an apartment building, was captured on a security camera across the street and shared on Twitter.

The video shows two people crossing the street near the building as its facade slowly peels away and crashes to the ground in a cloud of dust. The firetruck that appeared, almost instantaneously, was on its way back to a nearby station, the District fire department said on its Twitter page.

A passerby was hit by debris from the building, a fire department spokesman said.

The video was captured by Andy Feliciotti, who lives across the street. Photos Feliciotti shared of the aftermath showed part of the building listing to one side with roof beams hanging down. The sidewalk was covered in rubble.

Neither emergency crews nor a construction contractor could immediately say why the front of the building fell down.

Vito Maggiolo, a spokesman for the D.C. Fire and Emergency Medical Services Department, said that the collapse happened at 1:30 p.m. and that crews were on the scene for about two hours. They used a dog to check whether anyone was trapped beneath the rubble and did not find anyone.

“We do have structures that collapse from time to time,” Maggiolo said. “It’s not routine, but they do happen.”

The building was sold in September for $1.8 million, according to property records, and the following month the Department of Consumer and Regulatory Affairs issued permits for a renovation project that would create 18 apartments. The construction was projected to cost an additional $1 million, according to a contract filed with the department.

Maggiolo said the regulatory affairs department will be handling the follow-up investigation of the collapse.

Utku Aslanturk, whose company Dila Construction is listed as the contractor for the project, said he was still trying to determine why the facade had collapsed. Aslanturk is also listed as the contact for the limited liability company that owns the property.