— It was the costliest hazardous materials spill on a highway in Massachusetts in the past decade.

It happened on a dry, clear, sunny day just after 2 o’clock in Revere Beach, just north of Boston, on April 17, 2020.

A Department of Transportation report shows a tractor-trailer hauling gasoline mixed with ethyl alcohol took a roundabout much too fast and flipped over. The crash spilled the big rig’s entire load, nearly 10,000 gallons of liquid in all, onto Highway 1A and into a nearby saltwater marsh.

Police cited the driver, who was unhurt, for taking the curve at an unsafe speed. The cost of damage to the tractor-trailer, loss of gasoline, and cleanup of the marsh exceeded $1.1 million.