Manoa Falls Trail is off-limits until further notice. The Department of Land and Natural Resources says it closed the popular trail, Friday evening, after a rock slide brought down large "bike-sized" boulders, near the off-limits upper pool area. 

"Roughly four or five large size rocks had fallen on the Ahuialama trail and didn't quite make it to the Manoa Falls Trail," said Aaron Lowe, Trails Access Specialist for Oahu.

Initially, it was feared hikers may have been in the area, but after The Honolulu Fire Department conducted a search and rescue operation, it was found no one was injured.

On Saturday morning, Division of Conservation and Resources Enforcement (DOCARE) officers were at turned hikers away from the trail. 

"We came up to see the waterfall, but had to turn around..just cause it's unsafe," said hiker, Indigo Jorgensen.

Some people choose to heed the warning, while others did not. So far, no hikers have been cited. If someone is caught in a closed area fines can be as high as $500. 

"It's just rocks and you can see where it's actually slippery on the hill because the vegetation is all gone on the side of the waterfall," said another hiker.

In August, Manoa Falls trail was closed for three days to conduct a rockfall mitigation survey. DLNR adds that the upper pool area, near where Friday's rockfall happened, is unstable and has been closed for years.

According to DLNR, contractors will repel down to assess the Manoa Falls Trail,and see if there is any further risk or hazards. No timetable has been set for exactly how long it will be off limits to the public.