As the officers were investigating, a sports utility vehicle came along and crashed into the back of a pickup truck and another car that were stopped at the accident scene.
The SUV then rolled over and hit an HPD squad car.
Two people were transported to an area hospital with minor injuries.
There was an officer inside the police car when it was hit, but authorities said he was not hurt.
The freeway was shut down after the second accident, but then another wreck happened.
The driver of a Jaguar was speeding and did not see that traffic was stopped ahead, police said.
He came over the Patton St. overpass and tried to swerve, but slammed the passenger side of his car into the back of a Lincoln SUV. He also hit another car.
The passenger in the Jaguar died at the scene. The driver was transported to Ben Taub General Hospital where he was treated for minor injuries and his blood alcohol content was tested.
Officials said there were three people in the Lincoln SUV. A woman in the back seat was transported to Ben Taub in critical condition. Another woman was transported with minor injuries.
No one in the other car was injured.
The accidents shut down the North Freeway northbound for about four hours.