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A small plane landed on the roof of a building in a Pomona office park late Sunday afternoon, injuring the pilot and prompting a multi-agency response from emergency personnel, according to the Los Angeles County Fire Department.

The California Highway Patrol responded about 4:40 pm. to the interchange of the 10, 57 and 71 freeways after receiving reports of a downed aircraft, Officer Alex Rubio said.

A Fire Department supervisor initially said the plane landed but did not crash, adding that the building was on Corporate Center Drive, just south of the 10 Freeway. News video later showed the front of the aircraft had slammed into the top of the structure, creating a hole in the roof.

Kelly Vela said she and her husband were driving home when they witnessed the crash.

"It was going so low, I still couldn't believe that this was really a plane," she said. "Then, as we were watching it, that's when it hit and kind of bounced. And that's when I was like, oh my goodness, this is really a plane and not some kind of toy."

The single-engine Piper PA-28 was heading to Brackett Field in La Verne at the time of the incident, said Ian Gregor, a Federal Aviation Administration spokesman. The airport is about 4 miles northeast of the crash site.

Two people were brought down from the roof by aerial ladder; one of them was transported to a hospital by a Los Angeles County Sheriff's Department helicopter team, according to authorities.

The airlifted patient was the plane's pilot, who suffered moderate injuries, sheriff's and fire officials said. He was expected to survive.

The second person turned out to be not a patient but a good Samaritan who was on the roof trying to help, the Fire Department later said.

The plane remained on the rooftop Sunday evening. It was expected to be removed sometime Monday.

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