LONDON (Reuters) - The collapse of Baltimore's Francis Scott Key Bridge is likely to lead to a multi-billion dollar insurance loss, the chairperson of Lloyd's of London said on Thursday.

The massive Singapore-flagged container ship Dali sailing out of Baltimore Harbor bound for Sri Lanka reported losing power and the ability to maneuver before plowing into a support pylon of the bridge on Tuesday.

The impact brought most of the bridge tumbling into the mouth of the Patapsco River, blocking shipping lanes and forcing the indefinite closure of the Port of Baltimore, one of the busiest on the U.S. Eastern Seaboard.

The tragedy could lead to up to $4 billion in insurance claims, Morningstar DBRS said.

It was too soon to put a figure on the total insurance loss, Bruce Carnegie-Brown told Reuters, but he said he would be "very surprised" if the event did not result in a multi-billion dollar loss, adding that "the tragedy has the capacity to become the largest single marine insurance loss ever".

Lloyd's, which has more than 50 member firms, is active in the marine and property insurance markets, which are expected to face large claims from the damage to the bridge and the disruption in the port.

Lloyd's reported a 2023 pre-tax profit of 10.7 billion pounds ($13.49 billion) earlier on Thursday, boosted by strong underwriting and investment performance.

($1 = 0.7931 pounds)