TULSA, Oklahoma -

Five people have been arrested in connection with the death of a 66-year-old Tulsa man Monday evening during a home invasion robbery.

Tulsa Police arrested the five on complaints of first degree murder and armed robbery in the death of William Zachary, 66.

1/16/2012 Related Story: Tulsa Man Shot, Killed During Home Invasion Identified

The grandfather recently moved to Tulsa and was looking forward to his retirement.

The five suspects are identified as DeAndre Wright, 16; Montre Brown, 18; Uriah Mitchell, 18; Marquis Powell, 18; and Darrelle Johnson, 27. All five have been booked into the Tulsa County jail.

01/17/2012 Related Story: Tulsa Men Arrested In Fatal Home Invasion

His girlfriend says Zachary was kind-hearted, loving and a generous businessman, and his death was senseless.

"You know you'd like to sleep and wake up and it was a dream," said Sandra Lee, Zachary's girlfriend.

Lee's nightmare happened Monday evening when several men kicked in the backdoor, while Lee and Zachary were in the living room watching TV.

"We heard this huge crash. I thought some shelf had dropped, dishes or whatever," Lee said.

Instead it was a man with a gun, and another with a baseball bat, in ski masks demanding money. Even though he complied, Bill Zachary was shot and killed.

"He fired the gun again; I saw the flash of the gun again. When I turned around, they went out the door, and when I turned around I saw Bill on the floor," she said.

Lee says Bill Zachary had just retired last May from his hardware store in Kansas and moved to Tulsa, and was looking forward to travel and spending time with his four children, and nine grandchildren.

"Then it was cut short. I feel like he got robbed," Lee said.

Three suspects were arrested shortly after the crime. Tulsa police later arrested two more.

"They were going in backyards, looking in windows for things that they would want. Something in this house drew their attention," said Tulsa Police Sgt. Dave Walker.

Homicide Detective Dave Walker says that something was a gun safe.

"Messed up home invasion, messed up robbery, that led to murder," Walker said.

"Life's not fair. That's for sure," Lee said.

Four of the five suspects are teenagers, one is just 16. All are now charged with First Degree Murder and Armed Robbery.

"I would hope that other parents would pay more attention to their children. Where they're going and who they're hanging out with. And search them for weapons," Lee said.

Lee is overwhelmed by the senseless loss, how plans can suddenly change, and how life can be so brutally cut short.

"It's not right that good people are taken like that," Lee said.

Lee says Zachary will be buried in their hometown of Beloit, Kansas. She says we all should treasure those we love and to not put off telling them that, because we may not get another chance.