The shooting took place at Accent Signage Systems in the Bryn Mawr neighborhood in Minneapolis at about 4:35 p.m. Thursday, according to a statement released this morning by the Minneapolis Police Department.

The suspected shooter has been identified as 36-year-old Andrew Engeldinger, a former employee who recently lost his job at Accent Signage Systems, the Minneapolis Star Tribune reported.

Police wearing body armor began searching Engeldinger's home early this morning.

The bodies of the four victims were found shortly after police arrived at the scene while evacuating other employees, according to the police statement. Police have not officially named the gunman or the victims. Minneapolis Police Deputy Chief Kristine Arneson would only confirm that the shooter died from a self-inflicted gunshot wound.

The company's owner, Reuven Rahamim, was killed in the shooting, according to the newspaper.

Four others who were hurt in the shooting were transported to Hennepin County Medical Center. Three of the victims are listed in critical condition with gunshot wounds. The fourth victim had minor injuries, according to police.

"We received three patients who came to the hospital and they are in critical condition and they continue to be in critical condition this evening. They are three adult males," Christine Hill, the hospital's Media Relations Specialist, told ABC News Thursday evening.

Director of Operations John Souter and production manager Eric Rivers were among the four that were taken to the hospital, according to the Minneapolis Star Tribune. The other two victims in the hospital have not been identified.

Accent Signage Systems' website says the company makes interior signage and listed its founder as Rahamim.

Minneapolis Mayor R.T. Rybak said employees who were working when the shootings occurred were together and being cared for Thursday evening.

"We are deeply sorry about what has happened here," he said, calling the shootings "a horrible tragedy."