PHILADELPHIA (CBS) — At least two people suffered minor injuries after police and fire officials say a boiler exploded at an energy plant in South Philadelphia.

It happened around 3:15 p.m. Wednesday at Veolia Energy’s Schuylkill Plant in the 2600 block of Christian Street in the Grays Ferry section of the city.

“I just felt a shake, and a loud explosion-like noise,” said neighbor Nathan Witmer. “It felt like a tremor from an earthquake. That’s what I originally thought. I looked outside the window, and there were some other residents looking out their windows, and nobody knew what was going on.”

According to authorities, a homeowner living across the street from the facility was injured when the home’s windows were shattered from the blast.

Officials said an employee at the plant also suffered minor injuries, but refused treatment.

A fire department spokesman says crews were quickly on the scene and were treating it as a hazardous materials incident purely because it happened at an energy plant.

In a statement from Veolia Energy, the company said the incident was contained to inside the facility and there was no fire. The company said all employees had been accounted for and were okay.

The company said it will conduct a full investigation to determine what happened.