Employees inside a North Side business escaped injury Monday night as shots were fired at the building from the outside.
The gunfire was reported at about 7:45 p.m. at Pitney Bowes Presort Services, 1829 Wright St., Madison police said.
"Several rounds struck windows of an office where a technician was using a computer," said police spokesman Joel DeSpain. "Shell casings were found on the ground."
The business is a warehouse where mail heading to other companies is presorted.
No suspect information was released as the investigation continues.