CHICAGO (CBS) — Ald. Carrie Austin (34th) has been scarce since the raid by FBI agents on her ward office. She even canceled a town hall meeting set for Thursday night in her ward.

And Toni Preckwinkle, who serves as Cook County Democratic Chair said there’s no decision yet on whether to oust Austin as vice chair.

When FBI agents piled into Austin’s 34th Ward office and came out with printed documents as well as computers and electronic files, it sent a loud signal that federal prosecutors’ city council probe is far from over.

“The FBI and the U.S. Attorney’s Office here in Chicago is not going to take this step unless they think it’s going to lead somewhere,” said former federal prosecutor Jeff Cramer. “So these are not fishing expeditions by any definition.”

But the feds have certainly been pursuing some very big fish. Until the corruption scandals broke, Alds. Ed Burke, Danny Solis and Carrie Austin controlled the three most powerful city council committees.

Last November FBI agents raided Burke’s ward office and the finance committee he formerly rain.

Finance oversees all city expenditures including tax matters, contracts and bond deals, making it the single most powerful council post.

In raiding Austin’s office, federal agents took aim at the woman who, under Mayor Rahm Emanuel, chaired the budget committee. That committee was responsible for making sure Emanuel’s budget passed with few changes and little opposition.

And investigators amassed so much dirt on former Ald. Danny Solis (25th) that they forced him to wear a wire, recording conversations with colleagues including Burke for two years.

Solis formerly chaired the zoning committee, which oversees legal changes that developers desperately need to build major projects.

The pressure now faced by all three represents a sea of change for Chicago.

“With John Lausch at the U.S. Attorney’s Office and the current mayor at city hall, I think people can be cautiously optimistic that Chicago is making a turn toward reform,” said Cramer.

Austin has served in the city council for 25 years, which is second only to Burke.