An apartment fire in El Cajon on Saturday afternoon displaced 23 people from several apartment units.
San Miguel Fire and Rescue Department responded to reports of a fire at an apartment at 745 E. Bradley Avenue in El Cajon.
When firefighters first arrived, only a light smoke could be seen. Firefighters believe the fire started between the walls and spread quickly from there, into other units and up to the roof.
"You could smell electrical burning really bad. The coating on the wires was just melting everywhere," said resident Steven Boyer. "They've got guys putting holes in the roof to get it all put out."
In total, nine units were damaged in a fire that appeared to travel inside the walls and was thus hard to find, Battalion Chief Andy Lawler said. At least 23 residents and pets were displaced.
Lawler said the fire most likely started while a construction worker was soldering plumbing pipes in the wall of a vacant unit. The extensive heat from the soldering caused surrounding materials like drywall and wood to catch fire.
One man burned his hands in the fire, San Miguel Fire said.
The American Red Cross was called to help people find housing.
Lakeside, Santee and Heartland Fire-Rescue Departments also responded to the incident, as well as SDG&E.
No other information was available.