The scoreboard fire delayed the start of the Crew-United game on Saturday in Columbus, Ohio. (Mike Munden/The Columbus Dispatch)

It was difficult to conclude which spectacle was most disturbing Saturday night at Crew Stadium: the scoreboard fire that required two ladder trucks to contain and delayed the start of the MLS match by 50 minutes, or D.C. United’s abysmal first-half performance.

The blaze was extinguished. United’s humiliation raged on.

In a season that is unraveling by the week, United conceded three goals before intermission and lost its fifth straight, a 3-0 outcome in front of 14,090 spectators.

United (1-6-1) has failed to score in four away matches, and for the first time during this difficult spring, showed signs of cracking under the strain of mounting defeats.

Defender Brandon McDonald, who accepted blame for all three goals, said he “lost it” in the locker room at halftime. “I blame the whole thing on me. That’s unacceptable. . . . That’s terrible. That’s awful.”

Ethan White replaced him at the start of the second half.

Coach Ben Olsen tried to salvage positives, praising abundant scoring opportunities. He also said the game could have changed course had referee Sorin Stoica not disallowed Perry Kitchen’s apparent tying goal midway through the first half.

“We had a guy [McDonald] who had a bad night, and that is the way things have been going,” Olsen said. “We’ve been getting punished for any mistake we’ve been making. . . . We still have to make the plays that matter.”

Before United fell apart, a bizarre scene unfolded at the 14-year-old complex. The blaze began in the speaker system at the top of the primary scoreboard, located behind the south goal, about 30 minutes before kickoff.

As fire trucks roared to the scene and smoked poured from the structure, players were directed to the locker rooms and fans were cleared from the sections and concourse beneath the scoreboard. No one was injured, Crew officials said.

One ladder truck entered the stadium and took position behind the goal in order to douse the front side.

“We were looking to [fire officials] to tell us what the safety level was and for them to give us the green light to go forward,” Crew President Mark McCullers said.

With the public-address system not functioning, the fans sang the national anthem. The area was closed, primarily affecting 200 traveling fans from Washington. They were moved to an upper level in the 20,000-seat arena.

What the D.C. supporters witnessed on the field may test their allegiance.

For the fourth time this season, United conceded a goal in the first 15 minutes. McDonald misplayed a ball, leading to Eddie Gaven’s cross from the left corner. Jairo Arrieta pulled the ball down in front of Kitchen, touched it past McDonald and crossed into the six-yard box. Dominic Oduro slipped his marker, Daniel Woolard, and scored on a one-timer.

United thought it had drawn even on Kitchen’s header. “I don’t know what he was doing,” he said of Stoica.

United’s problems deepened three minutes later when no one cleared a routine corner kick. Josh Williams, a defender for the Crew (3-2-3), beat McDonald and skipped an eight-yard shot into the left corner.

United’s Kyle Porter struck the near post, and in a cruel and comical moment, a D.C. clearance deflected off Stoica at the top of the penalty area and bounded across the end line for a corner kick.

In stoppage time, McDonald knocked down Arrieta from behind in the box. McDonald fumed at Stoica before and after Frederico Higuain converted the penalty kick, the ninth first-half goal allowed by United this year.

United had several quality chances in the second half, but typical of the season, failed to hit the target.

“Nothing is going our way right now,” said defender Dejan Jakovic, who received several stitches after cutting his hand on a field-level sign. “It’s like there is a curse.”