Dozens of homes were evacuated here early Tuesday after a tractor-trailer ran off the shoulder on Interstate 84, tumbled down an embankment and began leaking highly volatile hydrogen gas.

The Connecticut State Police said the evacuations were taken as a precaution after the 18-wheel truck, which was traveling west and carrying 25,000 pounds of compressed hydrogen, hit the median, crossed the westbound lanes and ran off the side of the highway. The accident, which occurred about 5 a.m., damaged a valve on one of the containers carrying the gas, the authorities said.

Lt. Paul Vance, a spokesman for the State Police, said the interstate, a major east-west route that connects Massachusetts and New York State, was shut down to allow crews to unload the hydrogen containers. The Associated Press reported Tuesday night that the highway had reopened.

http://www.nytimes.com/2008/02/13/nyregion/13leak.html?ref=nyregion