LOUISVILLE, Ky. — It was a reasonable question: With the cloud hanging over the Alabama basketball team from a deadly shooting earlier this season, Coach Nate Oats was asked, had he and his players been able to enjoy their run to the second weekend of the N.C.A.A. men’s basketball tournament.
“Yeah, we’re having a blast,” Oats said of his team, which had garnered the top seed in the tournament. “We’re winning games. We know who we are. We’ve got a great group of guys that lean on each other, that have come close.”
After rolling to a pair of comfortable victories in the N.C.A.A. tournament, which followed a romp to the Southeastern Conference title, the Crimson Tide finally experienced slings and arrows on the court — and they crumpled under the duress, losing to San Diego State, 71-64, in a South Regional semifinal.
It was the third consecutive season Alabama had exited the tournament as a heavy favorite. The Crimson Tide were beaten the past two seasons by No. 11 seeds, U.C.L.A. and Notre Dame, but this loss — to the fifth-seeded Aztecs — carried with it a greater surprise.
Minutes after Alabama lost, the tournament lost its final No. 1 when Houston, which was trying to reach the Final Four in its home city, lost to Miami. It was the first time under the tournament’s current format that no teams seeded No. 1 had reached the round of 8, after Purdue and Kansas, last year’s champion, exited in the first weekend.
Alabama headed to the round of 16 with two other big threats in its region eliminated — second-seeded Arizona and third-seeded Baylor.
But on Thursday night, Alabama found itself bothered by San Diego State’s physical play and slow pace, and wasted a 9-point lead in the second half. Alabama’s star freshman, forward Brandon Miller, couldn’t rescue his team as he had regularly done this season, finishing with 9 points on 3-of-19 shooting and six turnovers.
Miller, hounded most of the night by Keshad Johnson, a chiseled 6-foot-8 senior, missed nine of 10 3-pointers — including one with 37 seconds left and Alabama trailing, 68-64. After a San Diego State free throw, Nathan Mensah blocked Jahvon Quinerly’s layup attempt — Mensah’s fifth block of the game — to all but seal it.
The Aztecs were lifted by Darrion Trammell, a 5-foot-10 transfer from Seattle University who poured in 21 points, equaling a season high.
Trammell and the Aztecs’ defense steadied themselves in the second half after Alabama had seemed to seize control. San Diego State crawled back from a 9-point deficit with a 12-0 run, holding Alabama scoreless for more than four minutes. Adam Seiko knocked in a 3-pointer to give the Aztecs a 51-48 lead, and Alabama could not muster a response.
When Jaedon LeDee spun through the lane and unleashed a rim-rattling dunk, the Aztecs’ bench — and their fans behind them — bolted out of their seats to celebrate a 60-53 lead.
“We just had a hard time answering the run they went on,” Quinerly, the senior point guard, said in a locker room that was more subdued than devastated, perhaps a sign of the wear that a turbulent season had taken.
If Alabama was drained emotionally, the Aztecs’ defense seemed to take the starch out of their legs. Quinerly was blocked on six layups in the second half, and the Crimson Tide had an abysmal shooting night, making just 3 of 27 3-pointers. At various points, their poise — and their fight — seemed to desert them.
“Our shot making could have been better, our shot choices could have been better,” said Miller, whom the school chose not to discipline after a police detective testified that he had transported the gun that was used in the shooting that killed Jamea Harris, 23. The district attorney has not charged Miller with a crime; he has been interviewed as a witness.
Since his presence at the scene became public at a pretrial hearing on Feb. 21, Miller has been the center of attention as Alabama has pushed forward, with national examination of the school’s handling of the case. Darius Miles, who began the season on the Crimson Tide, is in the Tuscaloosa County Jail on capital murder charges, along with his friend, Michael Davis, who is accused of firing the shots that killed Harris.
The scrutiny had not seemed to bother Miller’s performance much — until Friday.
At its best, Alabama races up and down the court, relentlessly attacking the rim and creating clean looks from behind the 3-point arc for its shooters. Whatever defensive intensity the Crimson Tide play with is often sparked by their offensive pyrotechnics. The biggest challenge for opponents is how Alabama can send wave after wave of elastic-armed defenders, led by 7-foot sophomore center Charles Bediako, a premier shot blocker.
“I’ve done this long enough to know we watch tape and we think this will work and that will work, and we’ll take advantage of that, and you step on the floor and you see their length,” Aztecs Coach Brian Dutcher said on Thursday.
But San Diego State, a physical, muscular team — a Mountain West version of Tennessee — did a masterful job of mucking the game up. The Aztecs grinded out each possession on offense and sprinted back on defense to shut off any transition opportunities for Alabama. When the Crimson Tide ran their offense, San Diego State covered gaps and raced to the perimeter to contest every shot and, with few exceptions, put a body on anyone lurking for offensive rebounds.
“Every screen, every drive, every rebound, we wanted to put a body on them,” the San Diego State assistant coach David Velasquez said. “That’s our No. 1 strength — be physical without fouling.”
If the Aztecs shot miserably — and sometimes passed the ball as if it were a live grenade — the halftime score was a work of art: San Diego State 28, Alabama 23.
But Alabama returned from the locker room having regathered its footing.
The Crimson Tide seized momentum — if not control — with just over 14 minutes left when San Diego State’s Matt Bradley dove on a loose-ball rebound of a missed Alabama shot. As Bradley corralled the ball, Bediako launched himself headlong on top of him.
Referee Don Daily whistled a foul on Bradley, which sent Dutcher into a rage, pounding the scorer’s table at the other end of the court.
As Daily warned Dutcher to calm down, another referee, Marques Pettigrew, slapped the Aztecs’ bench with a technical foul. Instead of possession of the ball and a chance to even the score, San Diego State watched as Miller sank two free throws and Noah Gurley tossed in a jump hook on the ensuing inbounds play, giving Alabama its biggest lead to that point, 40-34.
“Awful,” Dutcher told Daily as Miller shot free throws.
For Dutcher — and the San Diego State fans — the call echoed a previous trip to the round of 16 in 2011 when two technical fouls, including one on Kawhi Leonard, were pivot points in a loss to Connecticut, which went on to win a national championship.
“I said to myself, ‘Not again,’” Velasquez said.
There were more anxious moments down the stretch as Alabama sliced a 66-57 deficit with 2:12 left to 2 points with 46 seconds left. Alabama did not have to foul, but Rylan Griffen immediately fouled Bradley, who sank two free throws, and the Tide never scored again.
As the clock wound down, Oats stood on the sideline with his hands on his hips — an early end, once again, to a season, but not to the questions.