A deck that collapsed Sunday at a house in Rosemount, injuring three people who were on it, was constructed poorly and had been built without a city permit, officials said.

When the second-story deck gave way shortly before 4 p.m. at the house on Claret Avenue, homeowner Ed Finneseth said everyone was surprised.

"It happened right before my eyes," said Finneseth, who was going to follow his brother-in-law onto the deck Sunday afternoon. The family had gathered for Easter. "I turned to grab a deviled egg, and they were gone," he said.

The deck fell away from the house, landing on the patio below. Finneseth's wife, Jill, and brother-in-law suffered scrapes and bruises. His sister-in-law dislocated her ankle.

"It could have been so much worse," he said.

Rosemount building officials said the house, built in 1988, never had a permit for a deck. Looking at pictures after the accident, they noted multiple structural problems.

For starters, the deck was nailed directly to siding of the house, instead of being bolted to a ledger board, as required by building codes.

"This is one of the reasons why we require permits and inspections," said Kim Lindquist, the city's community development director. "It appears that there were some things that would've been caught at an inspection."

Finneseth said the deck was already on the house when his family bought it about 10 years ago. They hadn't noticed any problems before the collapse.

Nevertheless, deck builders from around the metro said homeowners should pay particular attention to their decks this year, given the long, snowy winter.

"That's a lot of weight on a deck surface," said Pat Noonan, owner of O'Noonan Construction and president of the Minnesota Chapter of the North American Deck and Railing Association.

That could create problems or exacerbate weaknesses in decks that weren't constructed by professionals, he said.

"Decks are one of those projects that unskilled homeowners tend to take on themselves," O'Noonan said.

Builders said homeowners should look for signs that the deck is pulling away from the house by checking the brackets that anchor it to the ledger board. It's also a bad sign if the deck is sloping backward toward the house, a likely indicator that the footings have shifted.

"Typically when decks collapse, it's not in the middle of the night when no one's on it," O'Noonan said. "That's why it's such a safety issue."

Katie Humphrey • 952-882-9056