Dallas police expecting to save a woman from a sexual assault were bewildered last week when they stormed an apartment after a six-hour SWAT team standoff, only to find the apartment had been empty the whole time.

Police were on the scene responding to a Dallas apartment complex where a bloodied and bruised woman had called 911 to say she had been sexually assaulted by a group of men.

"She was severely beaten up," a neighbor told WFAA 8. "Her eye was black and her nose was broke. I was trying to do the nice thing and let her know there's a hospital over here, but she was too terrified and scared."

The neighbor found a phone for the woman, who told cops that the suspects had barricaded themselves inside the apartment.

During the nearly six-hour standoff, Dallas police urged the empty apartment to "do the right thing" and surrender.

[image via Twitter]