University of Maryland all-America basketball player Len Bias collapsed in his dormitory suite early yesterday morning and two hours later was pronounced dead of cardiac arrest at Leland Memorial Hospital in Riverdale.

Evidence of cocaine was found in a urine sample taken at the hospital as an emergency medical team labored from 6:50 to 8:50 a.m. to revive him, police sources said. Maj. James Ross, head of criminal investigations for Prince George's County police, said even if cocaine had been detected, it would not be possible to tell if that had contributed to Bias' death without further tests.

Medical experts said sudden cardiac arrest in a 22-year-old in apparent top physical shape could have been caused by cocaine, by a heart ailment that even frequent examinations might have missed, or by a combination of the two.

Sources said Bias passed a physical -- including a urinalysis to test for drugs -- administered May 27 by the Boston Celtics, who Tuesday made him the No. 2 overall pick in the National Basketball Association draft. Bias showed no sign of a heart ailment in yearly team physicals, including a special study to look for hidden heart disease, and no evidence of drug use in urine tests last season, according to University of Maryland physicians.

From interviews with Bias' family, teammates and friends, a picture of his last hours emerges: He flew in from Boston with his father, went to the family home in Landover about 11 p.m., arrived at College Park around midnight, ate crabs in his dormitory suite with teammates and a member of the football team until about 2 a.m., drove off alone and was seen at an off-campus gathering, and returned to his dorm about 3 a.m. He collapsed some time after 6 a.m., while talking with teammate Terry Long.

Bias was unconscious and was not breathing when county ambulance attendants arrived at his dormitory suite at 6:36 a.m. -- four minutes after they were called and six minutes before a mobile intensive care unit arrived -- and he never regained consciousness nor breathed on his own, said Dr. Edward Wilson, chief emergency room physician at Leland Memorial.

Bias' body was taken to the state medical examiner's office in Baltimore yesterday for an autopsy. Dr. John E. Smialek, Maryland's chief medical examiner, said it would be seven to 10 days before complete autopsy results are obtained.

"We are not releasing any preliminary results," said Smialek. "We will wait until everything is properly evaluated."

The county's homicide unit is investigating, as is routine, but a spokesman said no foul play is suspected. All five teammates who shared the suite with Bias will be questioned, Detective Paul Noblitt said; Keith Gatlin was taken in shortly after 11 o'clock last night.

Bias' sister Michelle said she was told her brother was talking with Long on a couch in their dormitory suite in Washington Hall when he collapsed. A fire department spokesman, Maj. Thomas Brinkley, said Long was administering cardio-pulmonary resuscitation when the county ambulance arrived. It could not be determined who placed the call for assistance.

"He was sitting on the couch with Terry Long," said Michelle Bias, who was not at the dorm, "and he laid back like he was going to sleep and he started to have a seizure."

Details of what Bias did between midnight and 6:30 a.m. were vague. His sister said Bias and their father, James, flew in from Boston and drove directly to their home in Landover. "He Bias left home at 11:30 p.m. to go back to the dorm," Michelle Bias said.

Keeta Covington, a defensive back on the Maryland football team, said he was in the dorm suite when Bias arrived. Covington said he, Long, Bias and basketball players Gatlin, David Gregg and Jeff Baxter ate crabs and talked about the Celtics and Bias' future until about 2 a.m., at which point Bias left.

"He got tired of all the questions," Covington said. "He'd had microphones in his face for two days. We were just like the reporters. We were curious, only without pencils and microphones."

Covington said he walked with Bias to the parking lot, where he said Bias told him, "I'm getting away from here." Covington placed the time at "2 or 2:15."

Covington said Bias was merely tired of all the attention, not ill. "As far as feeling sick, bad -- nothing," he said. "He was trying to get away from the phone."

Bias drove off alone in his newly purchased Nissan 300ZX, Covington said. "I was under the impression he was going to see a lady," he said.

David Driggers, a friend with whom Bias often played pickup basketball games, said he saw Bias at a small gathering on Cherry Hill Road just off campus. "He stopped by and said how excited he was and talked for a while," Driggers said.

Driggers said there was no alcohol or drugs at the gathering. "Just soda," he said.

Driggers placed Bias at the party "around 2, 2:30," and Covington was quoted as saying Bias returned to campus about an hour after his departure -- which would have been about 3 a.m.

What happened between then and the time of Bias' collapse in the suite (shared by him, Baxter, Long, Gatlin, Gregg and teammate Phil Nevin) could not be determined. Long was not available to comment and Gregg declined to discuss it.

Nevin said he was out for most of the night and early morning, and when he returned he immediately went to bed, without seeing anyone. He said he awoke when the paramedics were taking Bias out.

Asked if he had seen any evidence of drug use, Nevin said, "I didn't see anything, but the police are going through it the suite with a fine-tooth comb."

Baxter and Gatlin both said they fell asleep earlier in the evening, and Gatlin said when he awoke he saw Bias on the floor and paramedics in attendance.

"I was in a state of shock," Gatlin said. "I was just worried about Lenny, he was on the floor. All my teammates and I just rushed up, got dressed, shorts or anything, and followed him to the hospital. I called his mother and just told her that Len had a seizure and they were taking him to the hospital, and she said, 'Okay, I'm going.' "

Neither of Bias' parents was available for comment yesterday.

At the hospital, Wilson said Bias "was unconscious . . . he never spontaneously began breathing on his own. He had no organized heartbeat."

Wilson said Bias was given five drugs in an attempt to revive him: sodium epinephrine (which he described as "basically adrenaline"), sodium bicarbonate (to normalize the acidity in his bloodstream), lidocaine (to control hyperactivity and any irregular heartbeat), calcium (to stimulate the heart muscle) and bretyline (a "secondary drug to control irregularity of the heart").

Afer the chemicals failed, Wilson said, a pacemaker was implanted in the heart muscle to try to get it beating. That also failed, he said.

Outside the hospital, Reginald Adams, a friend of Bias' and a player at Drexel University in Philadelphia, said he received a phone call at 7:30 a.m. from a mutual friend who said she was with Bias when he was stricken. "The only thing she said was he had problems breathing. He was breathing hard, getting cramps, then he just keeled over."

The woman's identity could not be determined.

In the medical examiner's office in Baltimore, Smialek said only the "initial phase" of the postmortem was completed.

Smialek said he had heard reports the hospital had found traces of cocaine in Bias' urine, but refused to say whether the medical examiner's office had found anything to suggest drug involvement.

"We obtained some of the urine sample that the hospital got and we are in the process of testing it, along with other samples obtained during the autopsy," said Smialek. "I'm not going to give any preliminary indication of anything so there are no misconceptions."

Washington Post staff writers Sandra Bailey, Tom Kenworthy, Eugene L. Meyer, Ed Nicklas and Dave Sell contributed to this report.