Orr's team of financial experts said that proposal was Detroit's one shot to permanently fix its fiscal problems. The team said Detroit was defaulting on about $2.5 billion in unsecured debt to "conserve cash" for police, fire and other services.
"Despite Mr. Orr's best efforts, he has been unable to reach a restructuring plan with the city's creditors," the governor wrote. "I therefore agree that the only feasible path to a stable and solid Detroit is to file for bankruptcy protection."
Detroit's budget deficit is believed to be more than $380 million. Orr has said long-term debt was more than $14 billion and could be between $17 billion and $20 billion.
Orr's decision to file now may have been influenced by lawsuits filed by some city workers and retirement systems to prevent Snyder from approving a bankruptcy request from the emergency manager, said Detroit-area turnaround specialist James McTevia.
They have argued that bankruptcy could change pension and retiree benefits, which are guaranteed under state law.
Orr has said federal bankruptcy laws trump state law in this matter.
(Read more: 3 Signs That Municipal Bonds Could Be in Trouble)
A bankruptcy judge will stay all the litigation, McTevia said. "One court will adjudicate all these.".
Some are concerned that a bankrupt Detroit will cause businesses large and small to reconsider their operations in the city. But General Motors, which filed and emerged from a Chapter 11 bankruptcy, does not anticipate any impact to its daily operations, the automaker said Thursday in a statement.
"GM is proud to call Detroit home and today's bankruptcy declaration is a day that we and others hoped would not come," the statement said. "We believe, however, that today also can mark a clean start for the city.
Detroit has more than double the population of the Northern California community of Stockton, Calif., which until Detroit had been the largest U.S. city ever to file for bankruptcy when it did so in June 2012.
Before Detroit, the largest municipal bankruptcy filing had involved Jefferson County, Ala., which was more than $4 billion in debt when it filed in 2011. Another recent city to have filed for bankruptcy was San Bernardino, Calif., which took that route in August 2012 after learning it had a $46 million deficit.
About 640 Chapter 9 bankruptcies have been filed since Congress enacted a revised Municipal Bankruptcy Act in 1937.
The White House said President Barack Obama and his senior advisors are monitoring the situation in Detroit.
"While leaders on the ground in Michigan and the city's creditors understand that they must find a solution to Detroit's serious financial challenge, we remain committed to continuing our strong partnership with Detroit as it works to recover and revitalize and maintain its status as one of America's great cities," said Amy Brundage, a White House spokeswoman.
- By the Associated Press.