The Williams garage caught fire at the Circuit de Catalunya as members of the Formula One team, including wheelchair-bound principal and founder Frank Williams, had gathered for a victory photograph.
"At that moment I was so scared for all of us," said Maldonado, the first Venezuelan to win a race and a 500-1 long-shot before sensationally putting his car on the front row in qualifying.
"I think we were so lucky because we had no big damage and especially because our people were okay," the 27-year-old added in a conference call from the team's factory in Grove, England.
Maldonado, who started on pole after McLaren's Lewis Hamilton was demoted to the back of the grid, was photographed carrying his 12-year-old cousin piggyback away from the smoke-filled pitlane.
The cousin had been wearing a cast on his foot from a previous injury.
"I saw my cousin who was with a small injury, I took him and brought him away from the box," said Maldonado. "It was a difficult moment for all the team but we've been so happy even after that because of the win."
The victory was the first for former champions Williams in nearly eight years.
Maldonado said he had seen happy faces at the factory when he returned to work, felt more motivated than ever and hoped to challenge again for victory in Monaco next week.
"We will do our best. As you see, all the teams are so close, the championship is so close and the gap is so close," he said. "We are getting better and better all the time.
"At the moment we don't have the quickest car on the track but we are doing our best and why not? Formula One is changing all the time. It's going to be difficult but we will try again."
The Venezuelan, a winner in the GP2 support series in 2010, said Formula One had become more competitive because of the Pirelli tyres and rule changes.
There have been five different winners from five teams in the five races so far, something that only previously occurred in 1983.
"The season is unpredictable. I think it is more competitive...it has become like a GP2 championship," added the driver who had been aiming for a top-five finish in Barcelona and then surprised everyone.
"It becomes very strong, the drivers can make the difference...it's a bit boring when you see only one car winning."
Seven-times world champion Michael Schumacher, who has yet to stand on the podium since he started his comeback in 2010 after three years out, has spoken out against tyres that have to be carefully managed and that penalise those who race flat out all the time.
Maldonado, who worked the tyres perfectly in Barcelona, said that was the name of the game.
"The tyre degradation is quite big and it is true that you need to manage them. This is part of the race and it's the same for everybody. There are no easy races. We need to adapt to the tyres, to the rules, to the car," he said.