Two workers at a town house construction site near Suitland were injured yesterday when one of the units collapsed, temporarily trapping one of the men and sending both to hospitals, Prince George's County officials said.

After the accident, which critically injured one of the workers, county construction inspectors halted work at the development in the 3400 block of Regency Parkway because of unsafe conditions.

One of the workers, Willard Washington, 45, crawled out of the debris created when the three-story building fell about 11 a.m. and was taken to the Prince George's Hospital Center with a rib injury, fire department spokesman Tony DeStefano said. A hospital spokeswoman said Washington was in stable condition yesterday afternoon.

The second worker, Kenneth Farrington, 32, was trapped temporarily, DeStefano said. Rescuers reached Farrington about 15 minutes after they arrived at the scene.

Farrington was taken to the Greater Southeast Community Hospital, where a hospital spokeswoman said he was in critical but stable condition with a pelvic fracture, several head cuts and a possible leg fracture.

Willie Furr, chief construction inspector for the county Department of Environmental Resources, said that his office issued a notice of violation for unsafe working conditions against the two men's employers, Regency Contractors.

"Everything has stopped there and no work will continue until a structural engineer checks on those buildings," Furr said. "If proper braces had been provided for the structure, it probably would not have fallen. But we won't know for sure until we get information from the structural engineer."

The structure that collapsed was the middle unit of five town houses, county officials said.

Efforts to reach Regency Contractors were unsuccessful.