strange "order by" request

Two tables - employee and timesheet simple enough. Each table is more
complex than example before. timesheet contains multiple rows per day
because the "other" fields are different for various rows on same
day/employee. My selection criteria actually uses some of these other
fields. lo_shift and hi_shift are always on the same date for a given row.

In the output, I *must* have all rows for an employee together, the
sequence of employees should be based on lowest value of "lo_shift" for
each employee. How do I code such a select?

Here are some commands to create tables & sample data:
CREATE TABLE "employee" (
"emp" character(6) NOT NULL,
"last" character varying(64),
"first" character varying(64)
);

CREATE TABLE "timesheet" (
"emp" character(6) NOT NULL,
"dept" character(2) NOT NULL,
"lo_shift" timestamp,
"hi_shift" timestamp
);

insert into employee(emp,last,first) values('091006','Clarke','Cynthia');
insert into employee(emp,last,first) values('096005','Mullins','Denise');
insert into employee(emp,last,first) values('089068','Johnson','Michelle');
insert into employee(emp,last,first) values('098036','Zandstra','Nicole');

insert into timesheet(emp,dept,lo_shift,hi_shift)
values('091006','10','2003-07-17 00:00','2003-07-17 07:59');
insert into timesheet(emp,dept,lo_shift,hi_shift)
values('091006','10','2003-07-17 08:00','2003-07-17 11:59');
insert into timesheet(emp,dept,lo_shift,hi_shift)
values('096005','10','2003-07-17 07:30','2003-07-17 08:59');
insert into timesheet(emp,dept,lo_shift,hi_shift)
values('096005','10','2003-07-17 09:00','2003-07-17 17:59');
insert into timesheet(emp,dept,lo_shift,hi_shift)
values('098036','10','2003-07-17 13:30','2003-07-17 19:29');
insert into timesheet(emp,dept,lo_shift,hi_shift)
values('098036','10','2003-07-17 19:30','2003-07-17 21:29');
insert into timesheet(emp,dept,lo_shift,hi_shift)
values('089068','10','2003-07-17 14:00','2003-07-17 17:59');
insert into timesheet(emp,dept,lo_shift,hi_shift)
values('089068','10','2003-07-17 18:00','2003-07-17 21:59');
insert into timesheet(emp,dept,lo_shift,hi_shift)
values('000032','90','2003-07-18 18:00','2003-07-17 23:59');

SELECT emp.emp, emp.last, emp.first, ts.lo_shift, ts.hi_shift
FROM timesheet ts, employee emp WHERE ts.emp = emp.emp
AND ts.dept='10' AND ts.lo_shift::date = '2003-07-17'
ORDER BY emp.first, emp.last, emp.emp, ts.lo_shift, ts.hi_shift;