ATF: Younkers fire 'undetermined'; hot work scrutinized

A long-awaited report on the cause of the March 29, 2014, fire that destroyed downtown Des Moines' historic Younkers building says the blaze's origin is "undetermined," but that embers from "hot work" can't be ruled out.

The widespread damage done by collapsing walls and intense heat left investigators with the federal Bureau of Alcohol, Tobacco, Firearms and Explosives unable to pinpoint the exact cause of the early-morning fire that gutted the building while it was being renovated into apartments, according to the 36-page report.

MORE STORIES ON YOUNKERS FIRE:

New downtown EMC building to cost up to $20 million

Wilkins project replaces plans on old Younkers site

Younkers remodel plans back on track

Reader's Watchdog: Des Moines to 'rethink' fire safety

Des Moines to 'rethink' fire safety Photos: Demolition of Younkers building

Demolition of Younkers building Videos of the Year: The Younkers fire

Investigators said that while they found no evidence of arson, they couldn't rule out a theory that the fire was caused by embers left from so-called "hot work" completed hours before the fire was reported.

That theory has become a central focus in an ongoing lawsuit over who is liable for damage caused by the fire. The suit is between several companies, including EMC Insurance, the Johnston-based Hansen Co., the project's general contractor, and the building's then-owners, the Madison, Wis.-based Alexander Co.

"The exact cause of the fire remains undetermined," the report's final page reads. "The degree of collapse and consumption caused by the fire and safety concerns precluded more extensive examination of artifacts in and around the area of origin. The 'hot work' being conducted on the afternoon of March 28, 2014, could not be eliminated as the potential cause of the incident."

Speculation about the fire's cause buzzed around Des Moines in the weeks after the iconic structure burned.

Jonathan Lund, the city's fire marshal, said it's not surprising a specific cause for the Younkers fire was not discovered, because the massive amount of damage hindered officials' ability to determine a cause.

"Fire investigation is a very delicate science," he said. "You have to be able to pinpoint the exact cause without any reasonable doubt. As you look nationwide, there's a fair amount of cases that go unresolved."

An "undetermined" finding does not mean that investigators don't have a theory about what caused the fire, said John Ham, an ATF spokesman for the Kansas City Field Division.

It only means that investigators couldn't prove that theory to the beyond-a-reasonable-doubt standard used in criminal cases.

Fire's spread detailed

The report detailing the investigation into the fire was released Monday to The Des Moines Register pursuant to a Freedom of Information Act request that was filed in January. The ATF redacted the names of investigators and people interviewed during the investigation.

The Walnut Street building was built in 1899 and was made up of two sections.

The western section, including the historic Tea Room, was spared from severe damage and is slated to be redeveloped into a 60-unit apartment building. The building's eight-story eastern portion was destroyed, and its remains were demolished.

Photos and videos of the fire, as well as interviews with firefighters and employees who worked in the building, showed the fire likely started "in or near" shafts of a passenger elevator, an adjoining freight elevator and a stairwell that sat on the westernmost wall of the eastern building, according to the report.

WITNESS ACCOUNTS: 'It just sounded like 100 car accidents happening at once'

FULL COVERAGE: Find more of the Register's award-winning coverage with photos, stories and video

Wooden stairs helped fuel the fire, and the elevator shafts and stairwell kept the blaze initially concealed as smoke filled the building, the report said.

The potential that the fire was caused by construction activities was raised in a lawsuit filed last year by EMC Insurance against the Hansen Co. and Alexander Co. Two downtown buildings owned by EMC across the street from the former Younkers store suffered approximately $8 million in damage from the intense heat.

The lawsuit argues the fire risk was heightened by ongoing "hot work" in the building, which included cutting with blow torches, as well as other factors. Both Alexander Co. and Hansen Co. have denied any wrongdoing, and a jury trial is scheduled for May 23.

Safety measures at question

The ATF report contradicts some of what Hansen officials said about safety precautions following the fire.

For instance, Hansen Vice President Tony Garcia said in a news conference the week following the fire that fire watches — closely watching an area for smoldering embers — at least an hour long were required after any hot work was completed.

But the ATF report indicated that not all the fire watches the day before the blaze lasted a full hour.

One worker from Des Moines-based C & C Demolition told investigators that on March 28, 2014, just hours before the fire was spotted, he finished hot work and began a fire watch at 3:10 p.m., poured water on areas where a torch had been used, and was out of the building by 4 p.m., according to the report.

That employee, whose name is redacted from the report, used an acetylene torch around 1:30 p.m. that day to cut a beam on the third floor of the east building that was near the elevator shafts and stairwell where investigators believe the fire started, according to the report.

He told investigators the work didn't cause any "excessive sparks" and that he covered the beam in water and placed it on a fire blanket after he finished the cut.

The same employee used a torch to cut beams around 2:30 p.m. that day on the second floor of the western building, according to the report. After the metal scraps had cooled, he tossed them down an elevator shaft, which he told investigators was a common practice as long as the pieces were cool.

He did an approximately 45-minute fire watch after those cuts.

He also cut metal columns and pipes in the basement of the western building around 7:30 a.m., according to the report.

Previous fires cited

Polk County District Judge Mary Pat Gunderson in June gave Hansen Co. permission to file its own lawsuit against C & C Demolition, which asks that if negligence by C & C is found to have caused the fire, the demolition company should be forced to pay the costs of any damages won by EMC.

The Hansen Co.'s lawsuit also lists West Des Moines-based Wolin Electric L.C. as a defendant, claiming the company was doing caulking that was considered hot work the day before the fire. The ATF report does not mention any hot work done by the company.

Garcia did not return a phone call from a reporter Monday. A lawyer listed for C & C Demolition also did not return a phone call.

The report offers some details about two fires before the fateful March 29 blaze. A Hansen Co. superintendent told investigators that a small fire broke out months earlier when workers were using a torch to demolish an escalator.

Then, a few weeks before the main blaze, the superintendent heard that a floor had caught fire while a torch was being used. The superintendent told investigators that the fires were quickly put out in both instances.

The lawsuit also alleges that Hansen often allowed heaters to run after work hours and allowed smoking throughout the job site. According to the ATF report, at least one heater was running when the fire broke out, and construction workers interviewed said smoking was entirely unrestricted.

Hot work as a culprit

A report issued recently by the Massachusetts-based National Fire Protection Association showed that over a five-year period U.S. fire departments responded to 1,230 construction site fires, 400 of which were at sites under renovation.

The fires' most common causes were related to hot work and careless smoking, the report said.

Des Moines fire officials received the ATF's initial draft report in April 2014. John TeKippe, the fire chief, said the report's conclusion was consistent with what Des Moines officials had discussed.

He also said he wouldn't speculate that hot work caused the fire.

"We can't exclude it, but I wouldn't speculate either that it caused it," he said.