Big Falls waterfalls in the San Bernardino National Forest is full of beautiful views and fun trails, but recent falls have officials worried that some visitors aren’t doing enough to stay safe.

On Thursday, a 46-year-old woman fell about 50 feet and “landed on rocks and suffered life-threatening injuries,” said Eric Sherwin, spokesperson for the San Bernardino County Fire Department.

“This is the third critically injured patient we’ve seen in a couple weeks, and the sad part about this is they’re all avoidable,” Sherwin said.

On Sunday, a 43-year-old man died and a 43-year-old woman was injured in a 20-foot fall near the same location.

“The working theory is that we have one large rock up at the top of the middle waterfalls that over the eons has become slick as glass due to water flow. Now, in the warmer months, we get moss growing on that rock, people then traverse that rock with wet feet and it’s a recipe for disaster we’ve seen repeat itself over and over again,” Sherwin said.

The areas most prone to slips are closed off with signage that tells people to avoid the area, but that doesn’t stop some people from going beyond the bounds of the trail.