The fire crew arrived just after 8 p.m. Saturday at the Old World Village’s German Restaurant, where an Oktoberfest celebration was in full swing. The restaurant owner, Bernie Bischof, led two firefighters to a patio area, which he’d cordoned off from patrons a few minutes earlier after smelling a strange odor emanating from an underground vault that held three transformers.

A week earlier, he’d heard unfamiliar noises coming from the vault.

As Bischof, two of his staff members and the firefighters approached the vault, an explosion tore off its 50-pound door and knocked them to the ground, said Jeff Lopez, a battalion chief for the Huntington Beach Fire Department.

“Our firefighters had to literally pick themselves up off the ground and figure out what was going on,” Lopez said Sunday morning. The explosion had thrown a burning material — believed to be mineral oil from inside the transformers — into the air, burning the firefighters, Bischof, a server and a security guard.

They scarcely had time to get up and realize what was happening when a second explosion rocked the Bavarian-style eatery “a minute or so later,” Lopez said.

The blasts shattered the beery euphoria of Oktoberfest and left many on Sunday wondering what caused them. It was the busiest weekend of the year for Bischof’s restaurant, which at the time of the explosion was filled with 1,000 people, or two-thirds the night’s expected turnout, said Dan Escamilla, a member of the restaurant’s management team who was tapped as its spokesman after the explosions.

Josef Bischof — Bernie Bischof’s father — came to the United States from Germany in 1952 and developed the enclave of Bavarian-style restaurants, shops and bars in Huntington Beach known as the Old World Village in the late 1970s, according to the village’s website and a 1986 Times article. Its inaugural Oktoberfest celebration was held in 1978.

Of the two firefighters and three civilians who were hospitalized Saturday night, all but one civilian had been released by Sunday, Lopez said. He declined to name the hospitalized civilian, citing privacy concerns. But Escamilla said the person was Bischof, who he said was in critical condition on Sunday at UCI Medical Center, having suffered second- and third-degree burns on 38% of his body.

After the explosions, Bischof ran out of the patio and into the restaurant, where two security guards wrapped him in a tablecloth to smother the flaming oil that clung to his arms, legs, flank and head, Escamilla said. The restaurant suffered no structural damage, and the fire in the patio area was extinguished within 10 minutes, he said.

Southern California Edison has replaced the three transformers that were within the restaurant’s vault, according to Robert Villegas, a company spokesman. An Edison crew initially had to wait on Saturday night to enter the vault because police were concerned the explosions may have been caused by criminal activity, Villagas said.

Those concerns weren’t borne out, however, and Edison was able to replace the transformers overnight and restore power by 9 a.m. Sunday to some 300 customers who were left without it overnight, Villegas said. About 1,700 Edison customers in all lost power for several hours after the explosions.

Edison has cataloged the damaged equipment and is investigating the explosions’ cause, which hasn’t been determined, Villegas said.

One of the transformers beneath the restaurant exploded in June 2010, according to Escamilla; the blast occurred early in the morning and no one was injured, he said. The transformers were making “strange noises” as recently as a week ago, which Bischof had asked Edison to look into, Escamilla said.

“Edison sent someone to check and they signed off on it,” he said. “Edison dropped the ball on this, simply put.”

Villegas, the Edison spokesman, said the company is still gathering maintenance records for the transformers and had no immediate comment.

Lopez, the fire chief, said the strange odor that prompted the restaurant’s staff to call the fire department was likely mineral oil overheating inside the transformers. He credited the staff for clearing the area of patrons, which he said limited the number of injuries to a handful.

“On a Saturday night, especially an Oktoberfest night, there’s a lot of people in that restaurant,” Lopez said. “It could’ve been a lot worse.”

Three-and-a-half hours before the transformers exploded, Escamilla said, a family was celebrating a 1-year-old’s birthday at a long table “two feet from the vault.”

“I have no doubt that if Bernie hadn’t cleared the area when he noticed the smell, people would’ve lost their lives,” Escamilla said. “There would have been 30 to 40 people in that area if he had not done that.”

He described the evacuation of patrons as “fast and orderly,” in large part because there had been an active shooter threat directed on Thursday at a movie theater screening “Joker” a few blocks from the Old World Village.

“We were already on high alert,” Escamilla said.

False accounts pedaled by members of President Trump’s inner circle threatened to poison U.S.-Ukrainian relations this year and gave Trump a cover for suspending military aid, a top advisor to Ukraine’s president said in his first interview with a U.S. news outlet.

“The fact is that some American politicians were not informed in the right degree about what is going on here,” Andriy Yermak said Saturday in an interview with the Los Angeles Times.

“This is both our problem and their problem,” said Yermak, who is a top advisor and longtime friend of Ukrainian President Volodymyr Zelensky.

“Clearly, over the years,” he added, “President Trump had developed a negative impression of Ukraine, which was not what we wanted.”

Yermak said he spent weeks this summer attempting to change U.S. officials’ decision to suspend a military aid package to Ukraine and was dismayed that the country had been dragged into Washington’s political fights and Trump’s possible impeachment.

Yermak chose his words carefully to avoid overt criticism of Trump advisors. But he clearly communicated a sense of betrayal and a hope that damage to Ukraine, which has depended on U.S. and European help against Russia, would be temporary.

Yermak was asked if he could trust the U.S. under Trump after all that had transpired in recent weeks, and a lengthy pause followed.

“We are pragmatic,” he said.

Ukraine’s relations with the United States have been favorable in the decades since it left the Soviet Union, turned to the West and stood up as a bulwark against Russia. The U.S. has provided military assistance that has helped Kyiv in its continued battle with Russian-backed groups that are trying to carve away parts of eastern Ukraine.

The hostile treatment by the Trump administration unnerved Zelensky’s government, which came into office five months ago and is still finding its footing.

Yermak has served as point man for connecting Zelensky with Trump through Trump’s personal lawyer, Rudolph W. Giuliani, whom Yermak met and spoke with several times in the months after Zelensky took office in the spring.

Yermak also helped broker the July 25 telephone call between Trump and Zelensky that now sits at the center of the impeachment inquiry.

On the call, when Zelensky asked about military aid, Trump responded, “I would like you to do us a favor though,” according to the account of the call released by the White House. He went on to press the Ukrainian leader to look at unsubstantiated allegations against former Vice President Joe Biden and his son as well as other false claims about Ukrainian involvement in the 2016 U.S. presidential campaign.

Those comments reflected allegations being promoted by Giuliani and fed by a former Ukrainian general prosecutor, Yuri Lutsenko.

Lutsenko suggested to Giuliani and others that there was evidence to suggest Ukrainian meddling in the 2016 election and illicit enrichment by the Bidens. He never supplied evidence and recently recanted the claims.

Determined to reverse the tide of Kyiv becoming isolated, Yermak exchanged text messages with U.S. diplomats from July through September aimed at setting up a meeting between Trump and Zelensky.

Some of the texts with Yermak and among the U.S. diplomats were released publicly by the House Intelligence Committee late Thursday. In them, U.S. officials pressed for a public commitment from Zelensky to open investigations into Biden and others.

“I think potus really wants the deliverable,” one of the diplomats wrote, using the acronym for president of the United States.

“I think it’s crazy to withhold security assistance for help with a political campaign,” wrote another of the diplomats, Bill Taylor, who was serving as the acting head of the U.S. Embassy in Kyiv.

Several days after the July 25 phone call between the two presidents, Kurt Volker, the administration’s special envoy to Ukraine, urged Yermak to draft a public statement that Zelensky could release to secure a White House meeting.

“Once we have a date” for a Trump-Zelensky meeting “we call a press briefing, announcing upcoming visit and outlining vision for the reboot of US-Ukraine relationship, including among other things Burisma and election meddling investigations,” Yermak wrote in response. Burisima is a gas company on whose board Biden’s son, Hunter, served.

“Sounds great!” Volker replied.

Volker resigned as envoy after he was named in the impeachment inquiry. He gave a deposition to the House Intelligence Committee last week in which he provided the text messages.

Pressure, meanwhile, was coming from other administration officials throughout the summer.

Zelensky and Yermak met with Trump’s former national security advisor, John Bolton, in Kyiv on Aug. 26; with Vice President Mike Pence in Warsaw on Aug. 31; and with Energy Secretary Rick Perry in mid-May. In all the meetings, the U.S. officials pressed the Ukrainians on corruption investigations, and the Ukrainians sought answers about why aid had been suspended. It is not clear whether Biden’s name specifically came up during those sessions.

In the interview, Yermak echoed Zelensky in saying Kyiv would resist outside pressure but added that much of what was being demanded of them, such as fighting corruption and reviewing past judicial cases, were things they would have done anyway.

He expressed dismay that Giuliani and other U.S. officials appeared to be woefully ignorant of Ukraine, basing their estimations on what he contended was the earlier government of Petro Poroshenko, which made advances in judicial reform but also faced corruption allegations.

“It is not a secret for us that the true information about Ukraine and U.S.-Ukraine relations left much to be desired,” he said.

After several telephone calls with Giuliani, which were arranged by Volker, Yermak met the former New York mayor in Madrid in early August. Giuliani had recently said in television appearances that the new Ukraine government led by Zelensky was full of “enemies of America.”

Ukrainian officials were stunned by that characterization. Yermak said he felt he had to speak to the lawyer personally both to dispel that notion and open a path to seeing Trump.

“I understood this was not an anybody, this was an opinion-maker,” he said of Giuliani.

Yermak says one of the government’s priority tasks now is to repair relations both with Washington and European capitals. The White House memorandum of Trump’s call with Zelensky quoted the Ukrainian as criticizing European leaders as he sought to flatter Trump.

Support from France and Germany are critical as Ukraine tries to negotiate an end to the war with the Russian-backed separatists.

After the call with Zelensky, Trump did release the nearly $400-million military aid package, and Yermak says his government has received assurances it will continue to flow.

“We made clear, however, that we want more,” he said.

As for his relationship with Giuliani, Yermak sent a note of thanks to the lawyer on social media. Giuliani responded in kind,but included Yermak’s cellphone number on the message – visible to millions of people. The calls flooded in.

Special correspondent Sergei L. Loiko contributed from Kiev.