By Jason Barry
Glendale, AZ (KPHO/CNN) - Residents in a Glendale, Arizona neighborhood are on edge.
For the third time in the past 15 months, someone has planted a pipe bomb in front of the same home and set it off.
ATF agents converged on a Glendale neighborhood early Wednesday morning after a pipe bomb exploded in someone's driveway. It caused damage to the garage door, the cars out front, and the roof.
Some pieces of shrapnel shot into the house and into an empty bedroom. The homeowners were asleep in another room.
Investigators say there were actually two pipe bombs, but only one went off. The other went flying into the vacant house across the street.
"That device could have easily killed anyone that was walking by. The velocity of that pipe bomb when it came apart entered the residence across the street thank god no one was killed," said ATF Special Agent Tom Mangan.
Once piece of the bomb smashed through the front window, it literally flew across the living room, went through a wall, into a bedroom outside, and smashed into the roof of the neighbor's house.
Homeowners Danh and Lan Nguyen are in the process of selling the house and feel fortunate they weren't home when the pipe bomb blasted through.
"I am very lucky. I moved out five months," said Lan Nguyen.
[Reporter: "Are you glad you moved out?"
"Yeah," said Lan.
The first two pipe bomb explosions occurred in June and July of last year.
No arrests were ever made, but security cameras may have caught the suspects this time.
The ATF is investigating.