SHREVEPORT- Authorities are responding to a construction accident at Willis Knighton Hospital in the 2600 block of Greenwood Road.

Construction crews were doing work when a building collapsed while at least 18 workers were inside. Reports say that three people have been rescued since the collapse, but others may be trapped. All have been rescued.

At a news conference on Friday, fire officials said nine people were treated for non-life threatening injuries.

The cause of the collapse is undetermined as of Friday at 11:45 a.m. Reports say that some workers were pouring concrete at different levels in the building when the collaspe occured.

This post will be udated when more information becomes available. Check back here and on WBRZ's Facebook and Twitter for updates.