Detroit’s municipal pension fund made payments for decades to retirees, active workers and others above and beyond normal benefits, costing the struggling city billions of dollars and helping push it into bankruptcy, according to people who have reviewed the payments.

The payments, which were not publicly disclosed, included bonuses to retirees, supplements to workers not yet retired and cash to the families of workers who died before becoming eligible to collect a pension, according to reports by an outside actuary and other people with knowledge of the matter.

How much each person received is not known. But available records suggest that the trustees approving the payments did not discriminate; nearly everybody in the plan received them. Most of the trustees on Detroit’s two pension boards represent organized labor, and for years they could outvote anyone who challenged the payments.

Detroit has nearly 12’000 retired general workers, who last year received pensions of $19,213 a year on average — hardly enough to drive a great American city into bankruptcy. But the total excess payments in some years ran to more than $100 million, a crushing expense for a city in steep decline. In some years, the outside actuary found, Detroit poured into the pension fund more than twice the amount it would have had to contribute had it paid only the specified benefits.“

This abuse of discretion was most egregious in 2009,” said Mr. Moore, a managing director at the firm of Conway MacKenzie. He said the pooled pension trust had lost 24 percent of the value of its assets that year, but the trustees appeared to have credited the individual accounts with 7.5 percent interest.

  Deal Book