This is from a Lithuanian site called Delfi Sportas. The below text is the Google-translate version of what appeared on the site:
46-year-old Lithuanian basketball legend Arvydas Sabonis on Tuesday evening, about 19-20 hours., Playing basketball and had a heart attack – a former athlete, straight from the sports hall was taken to Emergency Hospital, Kaunas.
Of course, this is all unconfirmed at the moment and it’s hard to really understand everything even with the translation, but it seems he may have suffered a heart attack while playing basketball.
Sabonis was just inducted into the Hall of Fame and is considerd to be one of the greatest European players of all time. We will update this post as this story continues to unfold.
Spanish website Cadenaser.com reports that Sabonis will apparently recover (again, translated via Google translate):
Although at first not revealed any information about his condition and the information published digital editions of the Lithuanian press was confusing, Ortega has said that Sabonis is out of danger. He also clarified that the former player was undergoing health examinations regularly.
(via Eye on Basketball)
The Blazers issued the following statement Tuesday afternoon: The Portland Trail Blazers have confirmed that Arvydas Sabonis has been hospitalized after suffering a heart attack in his native Lithuania. His condition is believed to be non-life threatening. Our thoughts are with Arvydas and his family at this time. We wish him well in a speedy recovery.”