No investigation was funded into the WTC collapses. FEMA instead assembled a group of volunteer investigators, the so-called building performance assessment team, BPAT.
Dr W Gene Corley, head of the BPAT said in testimony to the House of Representatives:
"The total amount of resources being dedicated to support the team’s activities is approximately $1 million, which has allowed the team to do the initial reconnaissance of the site and the building materials, begin the process of hypothesis setting, and conduct some limited testing. This raises the question of what amount of money would be sufficient. It is our opinion that $40 million would be a sufficient amount to fully fund a comprehensive study of an event of this magnitude and complexity".
So there was funding of around a million dollars. Corley wanted much more, however who would have known beforehand how much they were going to need? No comparable investigation has happened before.
However, lessons were learned, and in 2002 the National Construction Safety Team Act was introduced.
"The new legislation would give future building performance study teams early site access, subpoena power and up to $25 million per year".