It is believed the girl is just seven-years-old and that her mother had taken heroin when the clip was filmed.
The little girl can be heard pleading with her mother, who is swaying and obviously struggling to stay upright.
The video, which was posted to Facebook, has received over 400,000 views and led to a flood of calls and emails to the Philadelphia department of human services.
Speaking on their behalf, Anne Marie Ambrose told a UK newspaper: “While it is helpful that so many people emailed and called us after viewing the video, there were many people on the bus who witnessed this as it was occurring and took no action at all.”
Philadelphia police lieutenant John Stanford said of the shocking incident: “We don’t want people to engage because you don’t know what’s going on here. But we’d prefer you to call 911 or stop the operator of the vehicle.”
While the mother has been taken for police questioning, it is yet to be confirmed whether or not she was under the influence of drugs.
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