KATY, Texas -

Several neighborhoods in Katy experienced a lengthy power outage Wednesday night.

At the height of the outage, Centerpoint said there were 3,500 customers without power.

That number dwindled down to just a few hundred by nightfall.

Centerpoint said a substation caused the power outages. However, it does not know yet what caused the fault.

One resident, Terry Huckaby, said it did not appear to be a typical power outage. He said he saw his lights flicker on and off. His appliances started shaking. He said that was followed by a loud explosion.

"The power went out, came back on. It was erratic. It was like the lights were vibrating," said Huckaby.

The power outage was particularly uncomfortable for residents because Houston is in the midst of a heat wave. Customers had to endure several hours without power to run their air conditioners.