RICHMOND -- A Richmond building official said a deck that collapsed and injured 21 people was not properly constructed and was built without a required permit.

Commissioner of Buildings Arthur Dahlberg said his office found no building permit on file for the second-story wooden deck attached to an apartment building near Virginia Commonwealth University.

About 50 people were standing on the deck Friday night when it collapsed during a party, wedging dozens of people against the building.

Eleven of the injured are VCU students.

All are expected to recover.

Dahlberg said the roughly 20-by-20-foot deck was secured to the building with too few bolts and bolts that were too small.

Rust and rot also likely contributed to its instability, he said.

-- Associated Press