'RHONYC' Sonja Morgan Leaves Florida Restaurant in Ambulance, on Video

5:52 PM PT -- Sonja Morgan is explaining why she left a restaurant in Florida in an ambulance.

The 'RHONY' star tells PEOPLE in a statement ... "An elderly patron at the restaurant I was dining at appeared to be in distress, and I called for medical assistance. While assisting during the commotion, I sustained some minor injuries and, out of an abundance of caution, accompanied the EMTs to be checked out."

Sonja's statement continued ... "I'm incredibly grateful to the first responders for their swift care and professionalism."

She is also responding to our report that she was given a trespass warning from police ... telling the outlet, "I didn't want to leave. I insisted on making sure she was cared for."

1:10 PM PT -- Sonja Morgan was given a trespass warning last night, according to documents TMZ obtained from the Palm Beach Police Dept. She refused to sign the warning, the doc shows.

Sonja Morgan took an unexpected ride to the hospital last night ... and we have footage of her about to be whisked away.

Check it out ... our video shows "The Real Housewives of New York City" alum seemingly upset while loudly speaking to responding officers at Echo in Palm Beach, Florida, Thursday evening.

Sources tell us she chatted with Palm Beach police officers and restaurant staff for about 15 minutes before she hopped on the stretcher and was loaded into the back of an ambulance.

Ironically ... we're told Sonja called the ambulance for a friend who fell. Unclear how she ended up being the one cared for.

The Palm Beach Police Department confirms to TMZ officers responded to a medical call along with fire personnel around 9:45 PM last night and they stayed for less than an hour.

Palm Beach County Fire Rescue confirms a patient was treated at the scene.

TMZ reached out to Sonja's reps and the restaurant for comment ... so far, no word back.