HOUSTON -- Two people were shot to death in what police are calling a murder-suicide at a north Houston mall Tuesday morning.

Officials said shots were fired inside a store at Greenspoint Mall at about 10 a.m. The shooting occurred at Body Luxuries on the west side of the mall.

Lt. Albert Mihalco said the man confronted his girlfriend as she was opening the lingerie store.

Mihalco said she apparently struggled with the gunman, who moved her into a back room of the store and shot her in the head.

Seconds later, the gunman walked behind the counter and shot himself in the head, according to police.

The woman was wearing only her undergarments when both bodies were found. It is not known if she was sexually assaulted.

The shooter's and victim's names were not released.

The woman was the only employee at the store.

Those who knew the victim were in shock.

"She was a great girl. I just spent Sunday with her. She was really sweet," said Jacinta Gonzalez, the victim's grandmother.

"She was a very happy person. I don't know why somebody would do this," said Alma Benitez, the victim's former co-worker. "When I last talked to her, she said she was going to get married."

Houston police and the Harris County Sheriff's Department have a substation inside the mall, so officers were nearby to respond quickly.

"They heard one gunshot. They immediately secured the scene, did not approach the store any further. SWAT officers who were in the area training heard the call go out. They also arrived, cleared the store and found two victims inside the store," said Lt. Kevin Gallier with the Houston Police Department.

Other store employees said they were just starting to open their stores when a security guard and a mall Santa Claus ran down the corridors, pounded on gates and doors and told everyone to get out.

"I was standing behind the pole. Some were standing behind the sunglass booth -- some just watching to see if anything was going to happen," mall worker Glenda Amos said.

The mall's anchor stores were opened to the public from their exterior entrances on Tuesday, but the mall will be closed until Wednesday morning.

Greenspoint Mall is a 1.7-million-square-foot mall located on Interstate 45 at Beltway 8.