Four people were injured when an explosion rocked a Poway business Wednesday afternoon, San Diego Fire-Rescue officials confirmed.
Employees were told to evacuate the building housing Quantum Energy Storage on Gregg Street at 1:16 p.m., according to San Diego County Sheriff's Department.
The evacuation order affects other businesses in the same facility because the building has been deemed unsafe. Everyone must be out by 5 p.m., officials said.
All four people taken to the hospital have non-life threatening injuries, and a fifth injured person was treated at the scene.
One NBC 7 Twitter follower, who said she was a mile from the building, felt the ground shake when the blast occurred.
Witness Eler Gomez saw it all from across the street.
"The explosion, it go like 20 or 25 feet high with all the rocks and the concrete, this part of the roof," he said. "I went in there and I look and I see the roller doors missing, all the concrete on the ground. It was very very loud."
NBC 7 Facebook follower Jeanna Rodriguez tells us, "I was across the street at my office gym ... felt like a car crashed into my building."
While the company has not commented on the incident, investigators say the malfunction came from a circular device in the ground, which rotates and creates centrifugal force. The device exploded and sent pieces of the walls flying.
It even sent a 10-pound piece of steel — about the size of a catcher's mitt — rocketing over Scripps Poway Parkway into MC Suite, where Ray Butcher works. The building is nearly a quarter of a mile away.
"At that force, you're talking possible loss of limb. If it hit someone's head, that is a serious head injury," said Butcher.
Butcher and 14 other employees were just feet away when the debris crashed through the roof and onto a desk. Thankfully, it was unoccupied.
"Completely destroyed the cubicle desk and shot debris everywhere," Butcher said. When he stood up, there was a hole in their ceiling tiles, where daylight was peeking through.
According to investigators, the company had monitors and sensors, but they had no indication something was wrong before the explosion.
Poway Fire Department, San Diego Fire-Rescue and deputies responded. The SDSO bomb squad was called to investigate and the area is being handled as a crime scene but officials say that's procedure in this type of circumstance.
No hazardous gas or materials escaped into the neighborhood, sheriff's officials say.
The company Quantum Energy Storage provides secure, clean energy storage.