Someone living in an apartment complex called police just before 8 a.m. to complain about a cardboard box that smelled like chemicals. A resident moved the box to the sidewalk outside the complex on Francisco Boulevard.
Police evacuated about 15 residents for six hours as they called in the bomb squad.
They x-rayed the box and determined it was an improvised explosive device, so they detonated it with a water cannon.
Hazmat crews are still working to determine what the chemical was.