Java – hibernate cascading delete does not work as expected

I'm using hibernate 3 and trying to delete records in the database, and deletion doesn't work properly Pattern hibernate is opposing (in pseudocode):

create table Employer(
    employer_id number(12) primary key,employer_name varchar2(50)
);

create table Employee(
    employee_id number(12) primary key,employee_name varchar2(50),employer_id number(12) foreign key references employer.employer_id not null
);

create table Employee_Roles(
    role_id number(12) primary key,employee_id number(12) foreign key references employee.employee_id not null,role varchar2(50)
);

My hibernate class mapping looks like:

@Entity
public class Employer{

    @Id
    @Column(name = "EMPLOYER_ID")
    private long id;

    @Column
    private String name;


    @OneToMany(targetEntity = Employee.class,fetch = FetchType.EAGER)
    @JoinColumn(name = "employer_id")
    @Cascade(CascadeType.ALL)
    private Set