CINCINNATI -- A national museum commemorating the Underground Railroad is $5.5 million in the red just 18 months after opening, and officials said they will seek public money to continue operations.

When the National Underground Railroad Freedom Center opened in August 2004 with an annual budget of more than $10 million, officials said they would rely on admissions, donations and grants. But the center's chief executive, John Pepper, said income has not met expectations.

The center will seek city, state and federal funds rather than asking taxpayers to approve an operating levy, Pepper said. The museum will need an estimated $2 million to $3 million a year in public funding to stay up and running, he said.

The $110 million Freedom Center was built with $6 million from the city, $13 million from the state and $22 million from the federal government. Hamilton County built the $15 million platform and garage on which the center stands.