Rockford police called in a bomb squad on Friday after finding what they call "questionable compounds" inside a home in the 3,000 block of Kishwaukee Street. Neighbors watched fearfully as police raided the house.
"Anything could happen, if it was an explosion it could have blown up half the neighborhood," says Bill Penn.
Police are warning people not to go in the home or shed. They took several items from the shed, and neighbors say more equipment was taken out of the basement.
"They were taking stuff out, going in the back door out the front door, in the shed taking a bunch of stuff," says Christine Smith.
Police were conducting a narcotics investigation but are not saying exactly what they found.
"They took out a lot of lights, heaters, fans," says Smith.
Police are not releasing names of the four people arrested at the home. Neighbors say they never saw any suspicious activity at the house.
"For years a couple lived there. One passed away, one moved in last year I know. I've hardly ever seen him," says Penn.
A HAZMAT team tested some chemicals found at the home. There were no explosions reported.