On Friday afternoon, several hundred people were roaming the idyllic grounds of Chile’s national botanical garden, mostly unaware that, just across some hills and a highway, a raging wildfire was galloping toward them.

The danger quickly became clear. Rangers began racing around the park on motorbikes, shouting for visitors to flee to the exits. But by the time many got there, the fire had already arrived.

“Thick black smoke was billowing above us, so we laid down on the grass just inside the gate,” Alejandro Peirano, the park’s director, recalled Monday morning. “One of my rangers turned to me and said, ‘Director, are we going to die?’”

Elsewhere, three other rangers were trying to rescue a colleague, Patricia Araya, 60, a greenhouse keeper who lived in the park and was caring for her two grandsons and 92-year-old mother. They reached her cabin’s gate, but the fire was closing in. “I could feel the heat searing my back. I realized it was burning chunks of bark falling on me,” Freddy Sánchez, 50, said Monday, standing guard at the park entrance.

“We had to turn around,” he said. “All your body wants is to find a way out of the heat.”

The crowd that huddled on the front lawn survived — a miracle of sorts, given that 98 percent of the nearly 1,000-acre garden was destroyed.