June 30 in history: Launch of first emergency call service, addition of leap second to world’s official clocks and more

From the launch of first emergency call service to the addition of leap second to world’s official clocks, we've got it all covered.

Let's dive in today's history.

1859

Charles Blondin becomes the first to cross Niagara Falls on tightrope.

(Photograph:WION)

1937

World's first emergency call service "999" is launched in London.

(Photograph:WION)

1971

Crew of Soviet spacecraft “Soyuz 11” dies after the loss of air supply.

(Photograph:WION)

1972

Leap second is added to world’s official clocks for the first time.

(Photograph:WION)

2010

Nepal's PM Madhav Kumar announces his resignation in a televised speech.

(Photograph:WION)