Federal and state officials said Monday that they will investigate the collapse of an Amazon delivery depot in Edwardsville, Ill., that was struck by a tornado on Friday, killing six people.

Gov. J.B. Pritzker of Illinois said at a news conference that a state investigation into whether the building was constructed according to building codes was ongoing, while federal workplace safety regulators said they had opened an investigation after the collapse.

Company officials have defended their safety procedures.

At the news conference, an Amazon spokeswoman, Kelly Nantel, said the company believed the building was constructed properly, despite the catastrophic damage. “Obviously we want to go back and look at every aspect of this,” she said.

Mr. Pritzker said he was already speaking with lawmakers about whether the state’s building codes should be updated, “based upon the climate change we are seeing all around us.” He added, “That is something we are deeply concerned about, to make sure code is where it ought to be.”

The federal investigation will be undertaken by the local office of the Occupational Safety and Health Administration, which has had compliance officers on the ground since Saturday, said Scott Allen, a regional spokesman for the agency. He said the agency has six months “to complete its investigation, issue citations and propose monetary penalties if violations of workplace safety and or health regulations are found.”

John Felton, an Amazon logistics executive, said at the news conference with the Illinois governor that “everything that we have seen, it was all procedures were followed correctly.” He said the 46 people in the delivery depot at the time that the tornado hit acted “heroically,” using phones, bullhorns and other tools to move as many people to safety as possible.

Thirty-nine people sheltered in a space on the north side of the building that was “nearly undamaged,” Mr. Felton said, and seven people congregated on the south side of the facility, which fell directly in the tornado’s path.

The shelter spaces were not separate rooms, but were interior locations away from windows and other hazards, Ms. Nantel said.

Governor Pritzker said the risk of flooding in the industrial area where the building sits prohibited the construction of basement structures that could have provided better protection. He said there was an “ongoing look” at the initial confusion over how many people were at the building, which was staffed by many contractors who were not required to scan their badges when they entered the building at the end of their shifts.