BOSTON -- The criminal nature of the probe into the fatal Interstate-90 Tunnel accident will stretch back many years, as there were warnings from various sources about problems dating back to the late 1990s.

NewsCenter 5's Janet Wu reported Wednesday that Jim Kerasiotes was secretary of transportation, or chairman of the Massachusetts Turnpike Authority, for most of the 1990s. That's when most of the tunnels, now under scrutiny, were designed and built.

Kerasiotes did not want to speak on camera, but in a telephone interview he tried to put distance between himself and the tragedy. He said that he knows very little outside of what he is seeing and hearing in the news.

Kerasiotes left the Turnpike Authority in 2000 under fire for failing to disclose the mounting costs of the Big Dig.

"I don't know what happened, what construction happened when and what bolts went where. The ceiling panels were never on my radar screen. It wouldn't be unless someone brought it to my radar screen," Kerasiotes said.

Engineering consultant John Christian has been brought in to figure out what happened and why. He said that he'd have questions for Kerasiotes.

"What was he learning about what the stresses were on the people doing the work? Were they driven by schedule? Were there concerns about how these tunnels would be built?" Christian said.

Christian said that in projects of this size, pressure to meet deadlines often means compromise on quality or costs.

"I don't think there was any (deadline) pressure when that tunnel was being built. You have the professional construction managers to do the job for you. It's their responsibility to execute the job correctly," Kerasiotes said.

But Christian, who toured the site and inspected the debris for the first time Wednesday, said he is curious about why the roof of the tunnel in question was hung differently from most other tunnels in the Big Dig project.

"They then go in and attach the hangers to steel that is already poured into the concrete. That's a considerably more reliable system," Christian said.

Kerasiotes said that he empathizes with Matt Amorello, the current chairman of the Massachusetts Turnpike Authority. He said he can see the shock on Amorello's face during the daily briefings about the investigation.

Kerasiotes also concluded that politically, "somebody is going to get the slings and arrows." He said that it's a tragedy he "hated to hear" about, but he doesn't "have to answer the bell anymore."