Deck collapse injures 80

Preliminary investigation points to dry-rot in ledger leading to failure under load of patrons

Dry rot is now the suspected cause of a near tragedy at the Diamond Horseshoe Lounge and Grill last Friday night. City officials are also questioning whether the business exceeded its maximum occupancy load.

Polson made the national news last weekend when 80 people were injured during the collapse of a deck at the popular nightspot north of Polson bridge.

Patrons remembered hearing cracking noises just before the deck gave way around 11:30 p.m.

"It was crack, crack, wham. Then everybody went down," said Jason Nistler, a witness. "I actually stepped off the deck 20 to 30 seconds before it went."

The outer lights stayed on for about 20 seconds after the collapse and then all went dark.

"It sounded like a car came through the bar," said neighbor Steve Riddle. "It was a very, very, loud noise. It wasn't just a crack, it was a crumbling that went on for like 10 seconds."

According to several witnesses there were 100 - 150 people standing on the deck when it collapsed.

A 14-by-57-foot deck, a second smaller adjacent deck and the people on those decks fell approximately eight feet before hitting concrete below. The decks separated from the building and landed intact below, carrying the people atop them down too.

Many were trapped in a pile of people that fell toward the center of the deck as it collapsed.

Riddle, who lives a few doors north of the Diamond Horseshoe, described a "cheering" sound after that. He said he wasn't too concerned because to him it sounded like the roar of the crowd when someone scores a touchdown at a Grizzly game.

He arrived as people were pulling themselves to their feet. Many didn't realize right away that they were hurt, he said.

He added that emergency response was "awesome," and seemed to arrive within seconds after the collapse.

At first, "It was out of control … chaotic," Incident Commander and Polson Fire Chief Tom Maloney said. "Folks were screaming and yelling. Everybody wanted immediate attention when they probably didn't need immediate attention."

According to Maloney, the first emergency call was received at 11:48 p.m. Twelve ambulances responded to the scene - four from Polson and two each from Ronan, St. Ignatius, Kalispell and Bigfork.

He emphasized that inter-agency communication and cooperation were incredible.

In addition to help from other ambulance services and helicopter response from Kalispell and Missoula hospitals, fire trucks from Polson, Big Arm and Finley Point responded to the Diamond Horseshoe, while Ronan Fire Department sent equipment to Polson to cover the area in the event of a fire. The Columbia Falls ambulance service sent a crew to Bigfork to cover that area in case of an emergency there.

"It went like it was supposed to. You couldn't ask for a better working relationship. If it wasn't for the fact that we all work and train together a lot, none of this would've been able to take place," he said. "We gained control of the incident fairly fast … Having everybody transferred within an hour speaks for itself."

Maloney said that he and Polson Chief of Police Doug Chase estimate there were 150 to 200 people at the establishment when the deck collapsed.

There were 34 ambulance transports to local hospitals.

Nineteen people were taken to St. Joseph Medical Center by ambulance, with many more arriving there by private car.

A total of 54 patients were treated Friday night at the Polson hospital, while 17 were treated at St. Luke Community Hospital in Ronan.

Four people with what might have been life-threatening injuries were transported by helicopter from local medical centers to Missoula and Kalispell hospitals.

Another person who sustained serious injury was also transported, via ambulance, to Kalispell.

According to Maloney, the most common non life-threatening injuries were internal soft tissue damage and broken or sprained legs, feet and ankles that were jarred in the crash.

The next morning, nine more people were treated for aches and pains they experienced after the collapse, upping the grand total of injured persons to 80.

As of Tuesday morning, all but one of the four treated for possible life-threatening injuries had been released from the hospitals.

Ronni Boyce of Polson was scheduled to undergo surgery at Community Medical Center in Missoula late Monday afternoon. Her injuries include a broken elbow, broken hip and a fractured pelvis.

Other serious injuries that occurred in the Friday night collapse involved internal injuries and broken bones, with one significant compound fracture, Maloney commented.

To his knowledge, popular rumors that a person was impaled and another person had an appendage amputated are inaccurate.

The City of Polson hired building architect Paul Bishop to investigate the deck collapse.

In Bishop's official report, submitted to the city Aug 3, several building code violations were cited as the reason for the deck collapsing under the weight of "an undetermined number of bar patrons."

"The occupancy load for that business was under a hundred people," Maloney said, "It was our understanding that the occupancy load was given in 1990 when it was built."

According to Maloney, the non-technical version is that dry rot set in behind a wall ledger that was exposed to weathering, which caused the deck to eventually fail, since over time the structure was continually weakened.

Bishop included the following four "conclusions" in his report:

1. The wall ledger was not protected from weathering, as required by the building code. This allowed water to penetrate behind the ledger and create dry-rot which structurally compromised the ledger.

2. The lag screw were inadequate to support the code required load. The lag screws were also driven through the ledger, not through pre-drilled holes, which induced a splitting force. All of the lag screws were installed in the same plane, making the splitting force continuous for the length of the ledger.

3. The floor joists were connected to the bottom portion of the ledger only (the portion below the lag screw plane). This induced a critical load to the cross-grain section of the ledger.

4. As a result of these factors the ledger failed downward and outward as a result of vertical loading well below the maximum allowed by the building code.

Matt O'Neill, a local attorney who represents Diamond Horseshoe Inc., stated that Polson Fire Department visited the lounge twice in the last five years and that "the building passed inspection … (and) the deck was up to code."

Maloney confirmed that a building inspection was conducted in 1999 and that a separate fire inspection was completed on March 23, 2000.

Prior to Bishop's report being released, O'Neill stated, "Everybody is pretty confident that the deck was built with uniform building code - UBC."

He does not believe that a maximum occupancy was reached, as the security team members were continuing to let people through the door.

In the past when it's been too full, the security team denied people entry, O'Neill said.

There isn't a maximum occupancy for the deck, he continued, occupancy limits are calculated based on the total size of the facility, not room by room or by decks.

And this year's Hoopfest crowd was, in fact, smaller than past years, he added.

Bishop's report includes that "according to the building code the collapsed deck area of approximately 798 feet should have been able to support 100 pounds per square foot, or 79,800 pounds. At an assumed weight of 160 pounds per person this would yield a total structural capacity of nearly 400 persons. Obviously this number would not be feasible in the area of the deck…"

According to Polson city records, the deck was originally built in 1990, but the building underwent two remodels in 1999 to include the additional office space, and a bar and restaurant.

There were no additional deck building plans in the records. Apparently, the original deck built in 1990, was the deck that collapsed on Friday.

Maloney explained that Polson's fire department conducts fire inspections as often as possible, and that a change in the liquor license will often trigger a more frequent inspection.

A June 25 change in the Diamond Horseshoe's liquor license from Richard C. Myers back to previous (and now current) owner Berton Shultz initiated a pending inspection. According to Maloney, that inspection was scheduled to occur this week.