By Roger Schneider, Associated Press

FRASER (AP) – It likely will take until Thanksgiving to repair damage from a broken sewer line that caused a football field-sized sinkhole on Christmas Eve north of Detroit, a public works official said Wednesday.

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“Certainly, by the end of the year,” Macomb County Public Works chief Candice Miller said. “All of this done and the road, hopefully, depending on the weather.”

The cost of the work will be determined Monday when a contract is awarded to one of five bidding contractors that are all from Michigan, she said. She previously estimated costs at more than $78 million. She said they also took bids to inspect the entire drainage system, about 17 miles of pipes, to assess whether more work needs to be done to underground infrastructure.

“We are going to solve this,” she said. “It’s going to be a long-term fix, and by that I mean 100 years or more.”

Miller made the remarks at a news conference to introduce two Michigan State Police robots, named “Lucky” and “Wolverine,” that were then then sent into three condemned houses to make a video inventory of the properties. The robots are normally used by the bomb squad but were sent inside to ensure workers’ safety.

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“The robots can do anything we can do,” Michigan State Police Sgt. Ashland Bray said. “It can walk up and go down stairs, do whatever we need it to do.”

Miller said the information will be used to determine fair offers to the homeowners in the hopes of avoiding lawsuits. She said a budget of about $1 million was set to condemn and purchase the houses.

“We hope to have these homes demolished very soon, within the next couple of weeks,” Miller said. “They’re in a very unsafe condition.”

Authorities say the sinkhole arose due to a sewer pipe collapse about 45 feet under the ground. The resulting sinkhole is 250 feet long and 100 feet wide — larger than one in 2004 that caused a nearby section of roadway to cave in.

Gov. Rick Snyder declared a state of emergency in Fraser in January after visiting the sinkhole and seeing the problem firsthand with Miller and Macomb County Executive Mark Hackel.

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© Copyright 2017 CBS Broadcasting Inc. All Rights Reserved. The Associated Press contributed to this report.