Nope, it is not true.
Marvin Bush was never the head of security at the WTC.
Marvin Bush was on the Board of Directors, of a compnay called Securacom.
Securacom got the $8.3 million World Trade Center security contract in October 1996 and received about $9.2 million from the WTC job from 1996 to 1998. But in 1998, the company was "excused from the project" because it could not fulfill the work, and the electronic security work at the WTC was taken over by EJ Electric, a larger contractor.
Marvin Bush was reelected annually to Securacom's board of directors from 1993 through 1999. His final reelection was on May 25, 1999, for July 1999 to June 2000. Throughout, he also served on the company's Audit Committee and Compensation Committee, and his stock holdings grew during the period. Directors had options to purchase 25,000 shares of stock annually. In 1996, Bush acquired 53,000 shares at 52 cents per share. Shares in the 1997 IPO sold at $8.50. Records since 2000 no longer list Bush as a shareholder.
Ex FBI Agent John O'Neill was the head of Security at the WTC, he died in the attack.
The NYC Port Authority police were responsible for the security of the WTC, since they owned the buildings.
Police K9 Sirius... ...was an Explosive Detection Dog with the Port Authority of New York and New Jersey Police Department. Sirius, along with his partner, Police Officer David Lim, were assigned to the World Trade Center in New York, where their primary duty was to check vehicles entering the Complex, clear unattended bags and sweep areas for VIP safety...
On the morning of September 11, 2001, Sirius and Officer Lim were at their Station located in the basement of Tower Two.
So it seems your information is a little weak in facts.
Do more research and get back to us.