An enthusiastic group wore hard hats and used Hawaiian digging sticks to break ground yesterday at Kawaiaha'o Church's new multipurpose building.

Starting tomorrow, earth-moving equipment will begin to dig the foundation for the two-story building that will enable the church, which has been around since 1842, to extend its reach.

"The vision is to reach out to the community," the Rev. Curtis Kekuna told the congregation before the ground-breaking. "We want to serve the wider community."

Kawaiaha'o, the first church built on O'ahu, has been called the Westminster Abbey of the Pacific.

It is the final resting place of King William Charles Lunalilo, and is on national and state registers of historic places.

Once the center is completed, the church plans to renovate the preschool at the site and finish renovation of a basement at the church, which will have space for dance and choir classes.

The new facility replaces the Likeke Hall that was torn down last year. The new center will have classrooms, meeting rooms, a conference room, a social hall and a modern kitchen. In addition, a small museum displaying church antiquities will be in the new 30,000-square-foot building.

The old building, built in 1926 and expanded in 1940, was too small for most activities, said Don Caindec, project director. The new $17.5 million center should be completed by June 2010. Plans for it have been in the works since 2002.

"It's a significant day for us," said Valerie Trotter, a church trustee. "Kawaiaha'o will become a leader. This building will enable the church to expand its outreach to the community and to include many services that we were unable to hold here."

The site used to be a cemetery, Caindec said. The church has procedures in place should it encounter any human remains. When the original building was expanded in the 1940s, the church moved 117 sets of bones and re-buried them in Mo'ili'ili, he said.

"We don't anticipate finding any bones here," he said. "We did find a few bone fragments, and we have them in a temporary site in the basement of the church. We want to wait until after the excavation is done, and then we'll do a proper burial."

The church has established the Na Iwi Committee, a group of volunteers from the congregation and cultural experts from the community, to set up culturally appropriate guidelines and protocols to manage the cemetery.

About 500 people attend the church — one-fourth of the congregation in the 1950s and '60s.