WATCH: Two Trapped As Building Collapses in Sioux Falls, South Dakota

SIOUX FALLS, SOUTH DAKOTA—Two people are believed trapped after a building collapsed downtown around 10:30am central time.

First responders arrived on the scene quickly and were combing through the rubble for for a construction worker and female resident.

Sioux Falls news outlet KELOLAND reports:

 Sioux Falls emergency crews are working to rescue a woman trapped following a building collapse in downtown.

Sioux Falls Fire Rescue Chief Jim Sideras says crews have been in contact with her by phone.

“She doesn’t know where she’s at. She doesn’t know if she’s upside down or right side up. She’s disoriented because of her fall,” Sideras said.

pic.twitter.com/pZIucXMTWH

— Sioux Falls Fire (@SiouxFallsFire) December 2, 2016

Working as rapidly and safely as possible to locate individuals in collapse, construction related incident, please stay clear pic.twitter.com/7G8d74e4EF

— Sioux Falls Fire (@SiouxFallsFire) December 2, 2016

Authorities have not yet determined the cause of the collapse. Regan Smith with Sioux Falls Emergency Management said the building was under construction and that there was no explosion.