While the world is still trying to get its head around yesterday's sudden death of Heath Ledger, it's already time to start figuring out exactly what killed him.

The autopsy on Heath Ledger's body will take place today, meaning that it shouldn't be long before we know which of the conflicting stories about Heath Ledger's death – was it suicide? An accidental overdose? Pneumonia? – is most accurate.

Meanwhile, tributes have been pouring in from Heath's admirers, friends and family.

Following yesterday's shock news of Heath Ledger's death, fragments of the event are slowly coming together, although they by no means make a complete whole yet. So far we know that Heath Ledger was found naked, face-down and dead in his rented New York apartment by a housekeeper reminding him of an appointment with a masseuse. Various pills were found around the scene.

And, as seems to be the norm when an event as blindsiding as this occurs, several conflicting theories into Heath Ledger's death have been thrown up. Firstly, Heath Ledger's parents are claiming that if drugs were involved it was accidental:

"We, Heath's family, confirm the very tragic, untimely and accidental passing of our dearly loved son, brother and doting father of Matilda."

However, friends of Heath have darkly added that the death wasn't as unexpected as everyone is making out:

"This is terrible and I'm in shock. But to tell you the truth… we saw it coming. Heath has gone though a rough road of trying to get sober. Things were very dark. His one joy was Matilda. Everything else was misery for him. Unfortunately he was too late in getting help."

But that's not all, because TMZ reports that Heath Ledger was suffering from pneumonia when he died. And today the first steps of discovering the cause of Heath Ledger's death will be taken as an autopsy is carried out on his body. CNN reports:

An autopsy was scheduled for Wednesday as family and colleagues mourned the death of Academy Award-nominated actor Heath Ledger. "Pills were found in the vicinity of the bed," [police spokesman Paul Browne] told CNN. "This is being looked at as a possible overdose, but that is not confirmed yet." Browne later told reporters some prescription medications were found in the room, including sleeping pills. He said the pills were not "scattered about." No note was found and there was no indication of foul play, Browne
said. Ledger was found at about 3 p.m., and was pronounced dead at the
scene by emergency personnel about 3:30 p.m.

Meanwhile, tributes have been coming in from Heath Ledger's fellow actors including Mel Gibson, Nicole Kidman and John Travolta. Lindsay Lohan, who was reportedly having a casual affair with Ledger, was pictured looking 'extremely upset' just after news of his death broke. Warner Bros, the studio behind Heath Ledger's next film The Dark Knight, has expressed its sorrow but made no statement on how his passing will affect the release of the movie.

More news as we get it.

Read more:

Autopsy planned as actor Heath Ledger is mourned - CNN 

EXCLUSIVE: Heath Ledger's Friend: "We Saw It Coming" – UsWeekly