At least two people were killed on Monday when a small plane crashed into homes in a residential neighborhood of Santee in East San Diego County, authorities said, according to CBS8.

Two other people were also injured in the crash, officials confirmed.

The aircraft went down at the corner of Jeremy and Greencastle streets about 12:15 p.m. local time, according to the San Diego County Sheriff's Department.

Aerial footage showed two homes extensively damaged by fire. Large plumes of black smoke were also seen in the area.

Santee Fire Department Deputy Fire Chief Justin Matsushita confirmed Monday afternoon that there were “at least two fatalities” and two other people were transported to local hospitals. The injured parties were conscious when transported but the extent of their injuries was unknown.

Matsushita said he did not believe either of the fatalities were people inside the homes but the investigation is ongoing. He said it was unknown how many people were on the plane.

One of those killed in the crash was a UPS driver. UPS issued the following statement confirming the death of their employee.

“We are heartbroken by the loss of our employee, and extend our deepest condolences to his family and friends. We also send our condolences for the other individuals who are involved in this incident, and their families and friends,” the company said.

“We are cooperating with the responding authorities in their investigation, and we are respectfully deferring questions to the investigating authorities,” it added.

FAA officials were on the way to take over the investigation as of Monday afternoon.