Fiorina, a Republican, was speaking at a conference for women business owners at a hotel in San Antonio, when the top part of the stage fell down.
Watch the video here:
According to Patrick Svitek, who posted the video, everyone appeared to be OK.
Fiorina continued on a short time later.
.@CarlyFiorina returns to taking questions after curtains fall on her and others on stage in San Antonio.— Patrick Svitek (@PatrickSvitek) September 27, 2015
There's no word yet what caused part of the stage to collapse.