Surveillance footage shows the man rummaging through the register around 1:30 Wednesday morning. View Full Caption BRGRBelly

PORTAGE PARK — The BRGRBelly burger spot on Irving Park Road lost about $300 in cash and suffered more than $1,000 in damage when a man broke into the restaurant early Wednesday morning, its owner said.

The man smashed the back window of the restaurant at 5739 W. Irving Park Road at about 1:30 a.m. Wednesday, surveillance video shows.

He climbed inside and jammed open its register system to scoop out cash, said owner Steve O'Brien. The man also grabbed a six-pack of beer, but he left it behind.

When employees arrived to start preparing food early Wednesday morning, they found that the register had been knocked over and cleaned out, O'Brien said.

"I've lived in this neighborhood my whole life, and it's really surprising and disappointing to see something like this happen," said O'Brien, who opened the restaurant in 2013 with his wife Nicole under the name Leadbelly.

The couple took to Facebook Wednesday, typing a tongue-in-cheek plea for the community to help identify the "hamburglar."

" Originally we thought he was looking to steal our Battle of The Burger trophy or one of our award winning recipes but we were wrong," the post read.

Despite their playful response to the break-in, the owners are taking stock of a serious drag on their operation, Steve O'Brien said.

"A couple hundred dollars in cash may not appear to be a lot of money to someone who comes in like that, but with a small mom-and-pop business, that could be the difference between being able to make payroll, and not," he said. "When you rob from a business, you're robbing from individuals."

"There's no magic pill that's going to get that money back," he added.

Police are investigating the incident, O'Brien said.