Authorities have taken the first step toward a possible full-blown federal investigation into why the Dallas Cowboys practice facility collapsed.
The National Institute of Standards and Technology sent "a reconnaissance team of structural engineers" to Irving this week "to gather information about and examine the site of the collapse," agency spokeswoman Gail Porter said late Thursday.
She said the engineers interviewed city officials and Cowboys representatives, among others. She wouldn't comment on whether they also spoke with representatives of Summit Structures, the company that designed and built the tent-like facility.
Everyone who was interviewed "has been cooperative," Porter said.
Summit spokeswoman Laurey Peat said the company, which is based in Canada and Pennsylvania, "has never spoken with them and has received no call."
The steel-framed, fabric-wrapped structure fell apart May 2 during a thunderstorm that included a microburst - a downdraft of 70 mph or more. Scouting assistant Rich Behm suffered permanent paralysis below the waist, and 11 other people were injured.
Porter said that the engineers wrapped up their work Wednesday. They also collected documents, but she would not elaborate.
Key city documents related to the facility are missing, The Dallas Morning News has found. The city says it did not retain building plans or any other document showing which engineer certified the design.
State rules require that such records be kept for the lifetime of the building.
An employee in the city's inspections department said Tuesday that the city has no building or engineering documents for structures built before 1995.
The Cowboys facility was built in 2003.
Irving real estate and development director Brenda McDonald said the city would not comment on whether it was auditing such records or planning to revise current document-retention policies.
Irving gave the federal agency the same small packet of permit applications and inspections it gave The News last week, as well as a site plan, McDonald said.
She said her understanding was that the institute of standards and technology was "not coming down to determine fault or anything."
"They're really on a fact-finding mission to gather data," she said.
The Summit engineer responsible for the building design was Enrique Tabak, according to unsigned, uncertified plans obtained by The News. He was also Summit's engineer on a fabric-covered Philadelphia warehouse that collapsed a few months before the Cowboys facility was built, court records show.
Tabak has said he had little to do with the Cowboys facility.
Cowboys spokesman Rich Dalrymple declined to comment on the federal inquiry or his team's plans for the Valley Ranch site. Irving officials have granted the team a demolition permit, but it was not clear Thursday evening whether cleanup had begun.
Earlier this week, the silver frame of the collapsed structure sat in a mangled heap above the practice field. White shreds of the roof fabric dangled from the metal. Some large pieces of the support structure jutted out from a row of landscaping that separates the Cowboys' compound from a flood-control canal.
Last week, another institute representative said it was "hard to say" whether the collapse "would require the marshaling of our forces." Spokesman Michael Newman also said the agency would investigate only if the Occupational Safety and Health Administration asked it to do so.
Earlier this week, OSHA said it had not asked for help from the institute. It has said it does not have authority to investigate building design and construction.
Porter said the institute got involved after learning that OSHA wouldn't pursue those issues and communicating with that agency.
She cautioned that the institute's inquiry was preliminary. The reconnaissance team now must analyze evidence and recommend whether further study is needed into the cause of the collapse.
The agency also will determine "if there is an opportunity to improve building codes, standards and practices, or lead to further understanding about how structures perform under extreme loads," she said.
In 2002, Congress gave the institute the power and responsibility to look into building collapses that cause or have the potential to cause "substantial loss of life."