MORAGA — A vaping pen appears to be the cause of a 50-acre wildfire here earlier this month that had the potential to be disastrous, authorities said.

Police Chief Jon King said Tuesday that investigators found the pen at the “ignition point” of the Merrill Fire, which forced the evacuation of 150 people after breaking out around 1 a.m. Oct. 10.

“Right now, unless I saw someone actually light it, I don’t want to say that it’s the absolute cause,” King said. “But at this point, we’re not seeing anything else that caused it. But it’s more than likely.”

Authorities have not identified any suspects, nor have they made any arrests. King said that investigators have spoken to some people who were in the area where the blaze started and that they are looking for more.

King said last week, the fire appeared to be accidentally started.

Extra fire engines and water tankers, and extra firefighting personnel helped prevent the blaze from being worse. The fire did not burn any homes, and nobody was injured.

Morga-Orinda Fire District Chief Dave Winnacker said that without the extra resources, the blaze would’ve burned 10 to 30 homes, “no question.”

King also credited residents for cutting back their weeds in a fire-prevention measure.

“Having those (extra) engines rolling in so quickly made a huge difference,” he said. “When the wind shifted, and the blaze started coming down the hill toward houses, it slowed way down because of what the residents did to prepare. There weren’t as many fire fuels to keep it going. That was just as huge.”

Fire crews contained 80 percent of the fire and declared it under control by noon that day.

Anyone with information regarding the blaze, no matter how innocuous it may seem, was urged by King to call police at 925-376-2515.