Part of the garden is gated and tucked away a bit off the main path, but vandals found it over the weekend.
Crews were busy repairing a pipe that was damaged in the garden, and a Facebook post says the water and electrical systems were damaged in the attack.
A utility vehicle was also visibly damaged, and one worker estimated the damage at about $50,000.
They also knocked over a utility box. The Facebook post also mentions Eagle Scout projects and hours of volunteer work which was demolished. Employees called the vandalism heartbreaking, and fans of the park agree.
"I grew up in Oakland, so I've been coming here for years. I particularly like the Bonsai garden. So, it seems pretty senseless for someone to come in here and do damage to such a beautiful and serene place," garden visitor Robert Carroll said.
Friends of the Gardens of Lake Merritt are asking for donations to help make repairs. They are also asking for someone with carpentry skills to rebuild the tool box that was broken by the vandals.
The garden is still open, but people here are anxious to clean up the ugly behavior.
If you'd like to help, click here.