Application crashes when I delete the character pointer array

[arunkumaraymuo1]

try
    {
        char *testarr = new char[15];
        QString strVal1="Test";
        QByteArray br = strVal1.toUtf8();
        testarr = br.data();
 
 
        delete[] testarr; //Why my application crashes here.
    }
    catch(...)
    {
        QMessageBox::information(0, "", "Error");
    }

try
    {
        char *testarr = new char[15];
        QString strVal1="Test";
        QByteArray br = strVal1.toUtf8();
        testarr = br.data();


        delete[] testarr; //Why my application crashes here.
    }
    catch(...)
    {
        QMessageBox::information(0, "", "Error");
    }

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I have two questions

1) Why my above program crashes when I call delete[] testarr; ?
2) Why the catch block doesnot hadle that exception ?

I am using Qt creator 4.8 in ubuntu OS