BRIDGEPORT, Conn. (AP) _ Church bells tolled 28 times as hundreds of people gathered Saturday for a service in memory of the construction workers killed a year ago in the collapse of an apartment building.

''Look over your shoulders and remember the frailty of our humanity and the eternalness of our spirit,'' Monsignor William Scheyd, pastor of St. Augustine Cathedral, said just before ceremony broke up early during a sudden downpour.

Scheyd spoke in Wheeler park, which houses a monument to the 28 men killed in the L'Ambiance Plaza apartment building. The accident site is visible from the park, which is adjacent to City Hall.

Clergymen prayed and read each victim's name, and black-attired survivors of the victims huddled with politicians in dark suits and construction workers in jeans as the skies darkened.

As the cold rain got heavier, the small group of politicans standing under a covered platform who were scheduled to talk chose to end the ceremony early, before a moment of silence planned for 1:36 p.m., the minute that the building collapsed on April 23, 1987.

''There was something very symbolic here ... that we were covered and they (families and rescue volunteers) weren't,'' said U.S. Rep. Christopher Shays.

As the crowd quickly broke up, a lone construction worker in jeans and a green hard hat lingered in the heavy rain, then turned and walked slowly away, the last to leave.

Shortly after the ceremony, there were no mourners at the site. But two sprays of fresh red, white and pink carnations adorned the fence and a twisted blue sign with the name of the project still lay on the ground.

The memorial service began earlier at St. Augustine's, where clergymen encouraged survivors to reach out to each other and remember the outpouring of generosity from people around the world. They also noted that there had been two births and one adoption in victims' families in the past year.

''Although we were stricken by tragedy on April 23, 1987, we were not destroyed,'' Scheyd said.

''As we come here today to look back, let us not be afraid to look forward. The future will come for each of us.''

After the ceremony, several politicians and union leaders focused on the future of legislative efforts to improve construction safety.

''When people say this will never happen again, I wonder if it will,'' said U.S. Sen. Lowell P. Weicker Jr. He said a bill requiring employers to post a notice if dangerous chemicals were on a site was blocked by a recent Senate filibuster.

''Safety in the workplace seems to be a low priority with my colleagues and with the people,'' Weicker said.

''There was a tremendous showing here (today) - now we need to work on legislation and see this doesn't happen again,'' said Frank Carroll Jr., business manager for Local 488 of the International Brotherhood of Electrical Workers. ''The hearts of the families are still broken.''