A partial building collapse Tuesday injured three employees at a modular construction firm in Ephrata.

All three, who were welding at the time of the accident, were taken to the hospital.

Two were treated and released. The third was still being evaluated Tuesday evening, a spokesman for NRB USA Inc. said.

"Fortunately, there were no serious injuries," site general manager Donald Engle said. "We were very lucky."

About 50 employees were working in the building at 440 Wenger Drive, just behind the Redner's shopping center on North Reading Road, when a portion of the steel structure collapsed at 3:50 p.m.

No workers were caught underneath the collapse, which involved just a small part of the building. One employee was atop the section that fell and "slid down with it," Engle said.

"We kept him immobile until medical personnel arrived," Engle said. "At that point we had no idea of his injuries and wanted to take every precaution."

Engle said the employee was still being checked at a local hospital early Tuesday evening for broken bones and neck injuries.

The cause of the collapse wasn't immediately known, he said.

Ephrata-based NRB, established in 1979, manufactures permanent modular structures for a variety of uses.

Buildings are constructed at NRB's facility then shipped to and installed at another site. The firm ships to 16 states.

The building that collapsed Tuesday was being constructed for government use. Company officials kept media away from the building, which appeared to be covered with a tarp.

Law-enforcement and other local officials said they had no information about the nature of the project.

In the past, NRB has constructed a laboratory for the U.S. Environmental Protection Agency and buildings for detention centers in Somerset and Queen Anne's counties in Maryland.

The firm also has built structures for Starbucks and KFC.

Engle said workers would be able to return Wednesday and continue work on the structure that collapsed. He also said officials would begin investigating what caused Tuesday's accident.

"It goes without saying the safety and security of our employees is first and foremost.

"It's extremely important for us to determine what happened here today and make sure it never happens again."

Staff Writer Larry Alexander contributed to this report.
jtodd@lnpnews.com