KANSAS CITY, Mo. (AP) — A Kansas City Fire Department investigation attributes the deaths of two firefighters at least partly on the department’s culture of aggressive fire suppression.

The Kansas City Star reports that an internal report released Tuesday also cites a loose management style as possible factors in the October 2015 deaths of firefighter John Mesh and apparatus operator Larry Leggio.

The 71-page report says the firefighters were in an alley to protect a fire engine when a wall collapsed, killing the two.

Federal investigators are independently looking into the fire.

Thu Hong Nguyen operated a nail salon in the building and is charged with arson and two counts of second-degree murder in the case. She has pleaded not guilty.