The Port Landing project is shown in a rendering provided by MassDevelopment.

A minor “cave-in” atop workers Thursday shouldn’t slow construction at the Port Landing development near Kendall Square.

First described at 10:11 a.m. as a partial cave-in bringing cries for help from trapped workers, it was discovered by emergency responders to have affected only “a couple of rafters” at the scene of the 31,100-square-foot, 20-unit affordable-housing development at 131 Harvard St.

Two workers were injured in the second-floor incident as they fell about 10 feet, said Sean D. Hope, a local attorney and principal of co-developer Hope Real Estate Enterprises. The workers were taken to a hospital for treatment of leg and shoulder injuries.

An Occupational Safety and Health Administration team was brought in from Andover to look over the scene, officials said. But Hope believed the team would clear the construction site for work by the afternoon, and said construction was still on schedule for completion in August.

“We were at a meeting in Braintree and heard there was a fire, a roof cave-in, a collapse, and we were a little frantic. We got there and found out it was less [dramatic],” Hope said. “It was an unfortunate accident. Our focus now is on the guys.”

The official groundbreaking ceremony for the development was Sept. 21, a happy end of a saga in Cambridge development that began in the 1990s, when a development angling for zoning relief gave the 10,000-square-foot parcel to a group called Neighbors for a Better Community, where it languished amid controversy. Finally, in September 2015, Capstone Communities and Hope Real Estate Enterprises were able to get the parcel for development they touted as “the only new construction, 100 percent affordable-housing development to begin construction in Cambridge” that year.