Officials haven’t released the names of victims or the suspect.
Investigators are trying to determine the motive and were searching what they believe is the gunman’s home, FBI special agent in charge Paul Keenan told reporters late Friday morning.
“Nothing we learn can heal the wounds of those who escaped with their lives, but who will now … endure the memories of this horrific crime,” Indianapolis Mayor Joe Hogsett said at the same news conference.
Thursday night’s killings began when a gunman “got out of his car, and pretty quickly started some random shooting outside the facility,” Indianapolis police Deputy Chief Craig McCartt said.
The gunman then “went inside and did not get very far into the facility at all,” while shooting others there, McCartt told CNN earlier Friday.
“Thank God for being here because I thought I was going to get shot,” one of them, Jeremiah Miller, told WISH.
Investigators have heard the shooting lasted “just a couple minutes — that it did not last very long,” McCartt said.
“My understanding is, by the time that officers entered … the situation was over — that the suspect took his life very shortly before officers entered the facility,” McCartt told reporters.
Four people were found dead outside and four others, not counting the shooter, were dead inside, McCartt said.
‘Victims and witnesses running everywhere’
Police arrived “to a very chaotic scene, with victims and witnesses running everywhere,” McCartt told CNN.
No police officer fired, he told CNN.
Police have offered differing accounts of the wounded. McCartt said four survivors were taken to a hospital with gunshot wounds and a fifth was taken to a hospital with “some sort of injury” that he didn’t specify.
In a news release, police said five people were taken to a hospital with gunshot wounds and two other people were treated at the scene and released.
The gunman had at least one weapon, which investigators believe was a rifle, McCartt told reporters.
Police early Friday were trying to make sense of the crime scene while relatives of FedEx employees gathered at a nearby hotel, which officials offered as a place where they could await news, reunite with the workers and meet with police chaplains.
“Many of the employees did not have cell phones on them in the facility,” and so many survivors were not immediately able to contact their families, McCartt told CNN.
Sources: FBI looked into relative’s warning
It’s not clear when the suspect’s family member warned authorities, but the outreach was followed up by local authorities and the FBI, according to the three law enforcement sources briefed on the matter.
The FBI opened a preliminary investigation into any possible threat, but it eventually closed the inquiry after concluding there wasn’t sufficient evidence to continue it, according to the sources.
A spokeswoman for the Indianapolis Metropolitan Police Department declined to comment about CNN’s reporting.
“Once we positively identify who he is, we will be able to research further,” spokeswoman Genae Cook said.
When asked Friday morning whether witnesses indicated that FedEx or security personnel had any indication that something like Friday’s shooting would happen, McCartt said no.
“We’re still working with FedEx security for anything that might have been an indication this was going to happen right now,” McCartt said at the Friday morning news conference.
‘They didn’t sound like gunshots at first’
“They didn’t sound like gunshots at first … Then, we heard three more shots, and then my buddy … saw someone running out of the building.” Boillat said.
“And then more shots went off. Somebody went behind their car to the trunk and got another gun,” Boillat said, without saying whether that person was the shooter.
“And then I saw one body on the floor,” Boillat told WRTV.
Police are asking anyone who was at the scene and may have left for safety or for medical treatment to contact them to provide information on the shooting.
Governor and other officials offer condolences
Hogsett, the mayor, said the process of healing will be impacted in part by what conversations the nation has about cycles of violence “driven by readily accessible guns.”
“We must guard against resignation or even despair — the assumption that this is simply how it must be and that we might as well get used to it. We need the courage that compels courageous acts that push past weariness,” Hogsett said.
FedEx released a statement saying it was “deeply shocked and saddened by the loss of our team members.”
Indiana Gov. Eric Holcomb said Friday is “another heartbreaking day and I’m shaken by the mass shooting at the FedEx Ground facility in Indianapolis.”
“In times like this, words like justice and sorrow fall short in response for those senselessly taken. Our thoughts are with the families, friends, coworkers and all those affected by this terrible situation,” Holcomb said.
Flags will be lowered to half-staff from Friday until sunset Tuesday “in remembrance of those we’ve lost,” Holcomb said.
“I am communicating with local authorities to get all details of the attack and my office stands ready to help everyone affected any way we can,” he said.
CNN’s Shimon Prokupecz, Alta Spells, Meredith Edwards, Jason Carroll, Melissa Alonso, Madeline Holcombe, Joe Sutton and Keith Allen contributed to this report.