Tssk! Grammar, please?

These signs are up all over the place.
I found this one while walking back fro my doctor's rooms (with a big generator on the carpark) today.
It is near one primary, one intermediate and two secondary schools in Shirley, so I'm not surprised that someone has corrected the grammar ;-)

Mum braved the chaos and came into the city today. She got to feel one of our rumbly aftershocks while she was here. It was so good to see her.