PASADENA, Calif. — Worried customers with deposits in excess of insured limits flooded IndyMac Bank branches on Monday, demanding to withdraw as much money as they could or get answers about the fate of their funds.

With the failed bank now under federal control, hundreds of people lined up before dawn outside its headquarters branch in Pasadena.

The crowd swelled throughout the day, with customers seeking shelter from the hot sun under makeshift tents. Many waited for hours to get inside what became IndyMac Federal Bank after its takeover Friday by the Federal Deposit Insurance Corp.

"I didn't think this could happen," said Charles Tengeri, a retired schoolteacher who emerged from the bank with a check for $171,000 — an amount he said represented most of his savings.

"I'm glad to get anything out," he said.

Customers had been limited over the weekend to taking out funds through automated teller machines, debit card transactions and checks.

Customer Harvey Soldan spent Sunday night at a hotel near the bank so he could be among the first in line. With more than $100,000 in deposits, he anxiously waited to speak with bank officials.

"It's a question of how much we can get and how soon," Soldan said while waiting in line.

FDIC spokesman David Barr, who was stationed outside IndyMac headquarters, said it could take several years before the agency fully addresses customer claims.

"We have to completely unwind the affairs" of the bank, Barr said. "We may sell a portion to another bank, sell real estate. There may be lawsuits. There are a lot of different aspects to this."

IndyMac is the largest regulated thrift to fail and the second-largest financial institution to close in U.S. history, according to its regulator, the Office of Thrift Supervision.

IndyMac Bancorp Inc., the holding company for IndyMac Bank, had been struggling to raise capital and manage losses from bad mortgage loans.

The banking regulator transferred control of IndyMac to the FDIC because it did not think the lender could meet its depositors' demands amid a run on bank deposits by customers in recent weeks.

The FDIC insures bank deposits of up to $100,000 per depositor and up to $250,000 for funds in retirement accounts such as an IRA.

As of March 31, IndyMac had total deposits of $19.06 billion from some 275,000 deposit accounts. Of those, some 10,000 depositors had funds in excess of the insured limit, for a total of $1 billion in potentially uninsured funds, the FDIC has said.

The FDIC was telling customers with unsecured deposits that they would receive an advance dividend equal to half of the uninsured amount.