Cardinals head into the Sistine Chapel at the Vatican where they will elect the next Pope.

One-hundred-fifteen cardinals will choose the next leader who will need to tackle the daunting problems facing the Church at one of the most difficult periods in its history

After praying for divine guidance, they take a vow, never to divulge any details of their deliberations.

As the doors close the deliberations begin.

Crowds gather awaiting the news.

(SOUNDBITE) (English) PASSER-BY, JOHN CAMPBELL, SAYING:

"I think it's wonderful. I think Benedict was a great pope and I think everyone's very excited to see who the next pope will be, and so it's great anticipation wondering how different and how much the same he will be."

As night comes, black smoke signals that no pope is elected at the first conclave.

Voting will resume Wednesday with two rounds of ballots set for the morning, and two for the afternoon.