BRIDGEPORT, Conn. – For most of the past decade, Pakistani immigrant Faisal Shahzad struggled to find his place in America, piling up debts and bouncing from one run-down neighborhood to another.

In 2004, he and his wife, Huma Mian, plunked down savings to take out a $218,400 mortgage for a two-story house in Shelton, Conn., a gritty Bridgeport suburb. The following year, Shahzad was awarded a master’s of business administration degree from the University of Bridgeport, normally a ticket to a prosperous future.

But unable to pay the mortgage or a $65,000 home equity loan, the couple put broken furniture and old clothes up for sale when they and their two toddlers abandoned their home to foreclosure last summer. A heating oil company chased them for nonpayment of bills.

The portrait of failure that emerged Tuesday sheds new light on the 30-year-old former financial analyst — reportedly the son of a senior Pakistani Air Force officer — who U.S. officials say has admitted parking a 1993 Nissan Pathfinder packed with fireworks, gasoline and propane on one of New York’s busiest streets Saturday.

The car bomb failed to explode.

As the investigation intensified, neighbors and teachers described Shahzad as a loner who seemingly made few friends and little impression until now.

Shahzad was raised in Karachi, Pakistan’s largest city, and grew up in the North Nazimabad neighborhood, an upper-middle-class district of mostly Urdu-speaking, well-educated Pakistanis. Some family members still live there, officials said.

Shahzad came to the United States in 1998 on a student visa and studied business for five semesters at Southeastern University in downtown Washington, D.C. The college lost its accreditation last year and closed, but records found in the trash outside Shahzad’s home by a Connecticut Post reporter and posted online Tuesday indicate he was a poor student, getting mostly Cs, Ds and an F.

Shahzad managed to transfer to the University of Bridgeport in the late 1990s, and was awarded a bachelor’s degree in the fall of 2000, with a major in computer applications and information systems, according to spokeswoman Leslie Geary.

Tax returns found in the trash Tuesday show Shahzad’s income in 2000, when he earned his undergraduate degree, was $5,458. His 2001 return lists his occupation as an account analyst, and a gross income of $22,650.

Shahzad soon returned to the University of Bridgeport, and in the summer of 2005, was awarded the master’s degree.

Records show Shahzad and his wife moved repeatedly during his student days, renting apartments in Bridgeport and the other Connecticut towns of Milford and Norwalk. Neighbors said they spoke little English, and usually kept to themselves.

In 2004, the couple bought a two-story, three-bedroom house with an attached garage on Long Hill Avenue in Shelton, northwest of Bridgeport. Neighbors recall him working late at night, and then taking long walks.

Shahzad had landed a slot as a junior financial analyst in the Norwalk office of the Affinion Group, a marketing and consulting business, the company said. And his life seemed to improve.

In February 2009, he obtained a $65,000 home equity loan from Wachovia Bank. And on April 17, 2009, he became a U.S. citizen.

But two months later, in June 2009, he quit the job he had held for three years. That same month, he, his wife, and their children — a girl about 4 and a boy about 1 — walked away from their home in Shelton.