Authorities said they uncovered more bodies on Thursday from the wreckage of a US highway bridge that collapsed into the Mississippi River, and more than 20 people were missing.

A section of the bridge in Minneapolis plunged into the river during Wednesday evening’s rush hour in a deadly avalanche of steel and concrete, flipping dozens of vehicles into the river or onto the debris.

“Several (more) people are confirmed dead at the scene,” Minneapolis Police Chief Tim Dolan said, in addition to the four deaths already confirmed by the local coroner. Dolan would not be more specific about the toll on the Interstate 35W bridge. About 60 people were injured.

The death toll was almost certain to climb as recovery work continued.“These are horrible images but within each of those images is a story. That car you see tangled in the wreckage is someone’s cousin, brother or husband,” Minneapolis Mayor R T Ryback told reporters.

The 40-year-old steel-truss bridge carried at least 100,000 vehicles a day. The section of the bridge that collapsed stood about 65 feet above the river at that point.

Minnesota Gov Tim Pawlenty said in network television interviews the bridge had passed inspections, although it was among thousands of bridges across the country deemed to be “structurally deficient” in a federal government report.

Federal investigators were on their way to probe the cause. Witnesses to the disaster recalled people screaming, “We’re going into the water.” “There are cars in the water. A dozen cars are visible. We don’t know what’s underneath. We haven’t removed anything from the river. We’re are treating it like a crime scene,” a police official said.

Several workers who had been doing resurfacing work that closed some of the span’s eight lanes were among those hurled into the river.