Why is there a red line scanning my screen?

A

AC Question

I left my Galaxy S6 in my pocket during school and when I went to put my thumbprint in so I could access my phone a horizontal red line appeared. The line moved up and down my screen - like a fingerprint scanner in those high tech movies - and now the touchscreen is unresponsive so I cant even turn it off to factory reset it. I've tried hard resetting it everyway shown on here and nothing has worked.