UPDATE (12:57 p.m.): Officials say one of the workers was using a power washer at the site, which ignited fumes.
UPDATE (12:40 p.m.): Two people have been hospitalized following the explosion, according to first responders at the scene.
There is currently no fire, and investigators suspect fumes led to the blast.
Elmira and Southport Fire Departments are responding to a possible explosion at the former Tops plaza in Elmira.
Smoke could be seen coming from the plaza.
Tops Friendly Markets announced in October that the building was being closed along with nine other under-performing locations.
We will have more on this story as it develops.