The bomb squad secured the bank and sent a robot to retrieve the device, which turned out to be fake.
"I believe it was a homemade hoax bomb," said Sergeant Mike Harvey with the Harris County Sheriff's Office. "It does not appear to have been a real device, but it was constructed well. It looked like a real device. And the teller was smart. She didn't touch it."
The robber got away in a white Impala. Authorities are looking for him now.