The standoff lasted hours before the gunman shot himself in the head. Police have identified the suspect as Roy Lee Ferguson, 48.
Valparaiso Police Sgt. Michael Grennes says police received a 911 call about 10 a.m. reporting that a man with a gun had entered the Prudential Executive Group Real Estate office in the 2600-block of North Calumet Avenue. Grennes says there was a "brief exchange of gunfire" when officers arrived.
Police say the man went into the business because he believed someone there owed him money.
With police and other emergency personnel swarming outside, Prudential controller Carolyn Biesen hid under her desk for more than an hour after the gunman entered the office.
"Our office manager is at the front desk and she's yelling, get out, get out. And I came out and I just yelled, and I go, get out. At that time, he pulled a gun," said Biesen.
After nearly seven hours surrounding the building, SWAT team members went in after the gunman who had released all of his hostages earlier. They found him on the ground in the office. Paramedics transported him to the hospital where they pronounced him dead.
"The situation like this, obviously we would like to have everybody come out safe. It's unfortunate this individual, the way it ended," said Chief Michael Brickner, Valparaiso Police Department.
Biesen says she and a co-worker were two of 10 people in the office when the gunman entered. The gunman may have been unaware of the total number of people because many hid in offices under desks where they talked to 911 operators at the same time.
"I felt safe under the desk, I felt safe on the phone with the police," she said.
The company's owner, Larry Hitz, said the gunman apparently had a dispute over money with an employee who was not even in the office Friday. He had also been there Thursday, prompting the company to seek a restraining order. But there was no way to stop the gunman Friday.
"He just barged barged in and started hitting women," said Hitz.
The police say Ferguson hit the receptionist right when he entered the office. She was taken to Porter Hospital where she was treated and then released.
Police kept communication with the gunman while they closed off the normally busy intersection and surrounding businesses in Valparaiso.
"It was a little scary," said Rella Baker, who manages a video store that shares a parking lot with the realty office. "You just never know what's really going on. I didn't really know."
Police tell say that none of the hostages was seriously injured .