ESPN -- Investigating Reporter Who Berated Tow Truck Employee [UPDATE]

2:10 PM PT -- ESPN just suspended McHenry for one week.

1:30 PM PT -- McHenry issued an apology on Twitter, saying, "In an intense and stressful moment, I allowed my emotions to get the best of me and said some insulting and regrettable things. As frustrated as I was, I should always choose to be respectful and take the high road. I am so sorry for my actions and will learn from this mistake."

ESPN tells TMZ Sports ... the network has launched an investigation into reporter Britt McHenry -- after footage surfaced showing her recently BERATING a towing company employee.

The footage is shocking -- appearing to show McHenry GOING OFF on a worker while trying to get her car out of an impound lot in Virginia ... ripping the worker's appearance, education and financial status.

Oh, and she dropped the epic, "I’m in the news sweetheart, I will f***ing sue this place."