Ald. Deb Mell’s 33rd Ward office in the Albany Park neighborhood was burglarized early Monday on the Northwest Side, police said.

About 3:25 a.m., the male suspect broke in through a glass pane front door at the ward office at 3001 W. Irving Park Rd., authorities said.

The thief threw a chunk of concrete to shatter the glass.

“It doesn’t feel great, but it happens,” Mell said at her office later Monday.

A man who lives nearby and was cleaning the office early Monday startled the thief, who ran off with a computer tablet, Mell said. The tablet is left in the front window of the office to display Bus Tracker information for the nearby No. 80 bus stop, Mell said.

No one was in custody early Monday as Area North detectives investigated.