Adam Lanza shot and killed 20 children and 6 adults at the Sandy Hook Elementary School in Newtown, Connecticut.
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One of America's oldest documented highways was completed on this day in Connecticut, USA.
The first commercial helicopter, Sikorsky S51, had its first test flight.
The first telephone directory was issued, which consisted of a single card with 50 names and addresses in Connecticut, USA.
Connecticut became the 5th state to join the United States of America.
The first ballistic missile submarine was launched from Groton, Connecticut, US.
