Mount Isa mayor Tony McGrady told two mothers  the Family Fun Park and Skate Way Park were unsafe for children because of a ripped $30,000 shade sail and a dismantled brick wall.

``Aw, that's so sad,'' one of the mothers said.

The mothers compromised by taking their children to another park, which would not have had the same  facilities.

Cr McGrady said the ripped shade and damaged wall were caused by ``grubs'' in the early hours of yesterday morning.

``Jesus, it makes you cry,'' he said.

``Can you imagine if kids were running there if a wall collapses?'' 

Council staff cleared the scattered bricks in the park before 9am yesterday.

Another $16,000 shade sail was damaged last Thursday night in the Family Fun Park.

Cr McGrady said council staff were working hard on the tight local budget, deliberating over funding as low as $300.

``And in one fell swoop these people come in and smash a $30,000 sail, a $16,000 sail,'' he said.

He urged Magistrate Rod Madsen to be firm with the vandals if they were brought to the Mount Isa Magistrates Court.

``I have to say I don't think anything is too harsh for the grubs who do this,'' Cr McGrady said.

Mount Isa Police Sergeant Simon Tayler said police were ``exceedingly disturbed'' by the vandalism.

The Family Fun Park is fenced but people could easily climb into the area if they were motivated, Sergeant Tayler said.