CHICAGO (CBS) — On the anniversary of Dr. Martin Luther King Jr.’s assassination in Memphis, union workers in Chicago are calling for a fair contract for janitors as they threaten to strike next week.

As WBBM Newsradio Political Editor Craig Dellimore reports, on this day on 1968, Dr. King was gunned down while supporting striking sanitation workers in Memphis. Now, members of Service Employees International Union Local 1 say it’s an appropriate time to act on behalf of 13,000 janitors at downtown buildings, schools and elsewhere.

LISTEN: WBBM Newsradio Political Editor Craig Dellimore reports

The Rev. Calvin Morris, director of the Community Renewal Society, was among those calling for justice for janitors.

“They deserve a good contract. They deserve benefits. But most of all, which Dr. King said 44 years ago in Memphis, as working men and women, they deserve respect,” Morris said.

The workers have authorized a strike, but SEIU officials say they hope it does not come to that. Wages and health insurance are the major issues are the major issues.

If a strike goes ahead, some of the buildings and offices that would be affected by a strike include Bank of America, JP Morgan Chase, General Electric, CME Group, Boeing, AT&T, Kraft, United and Tishman Speyer.

The janitors voted to authorize the strike over the weekend. They also rallied at Teamster City at Ashland Avenue and Jackson Boulevard on Saturday.

SEIU cites the Economic Policy Institute’s calculation that the cost of living for a family of four in the Chicago area is $51,319 a year – $20,000 more than the average janitor makes.

The contract covers:

–4,000 janitors in downtown commercial office buildings
–3,000 in suburban commercial office buildings
–2,700 in public schools and City of Chicago facilities
–3,500 in malls, universities and other buildings.

Bargaining is set to resume Friday.