Port Credit ushers in the fifties with 675 students and 23 teachers, but change is inevitable. By the middle of the decade the school population nearly doubles and Port Credit High quickly expands under a new name: Port Credit Secondary School. The creation of new schools like Graydon and Lome Park helps by diffusing students across the growing region. Nevertheless, Port Credit needs a new wing to accommodate ever-growing numbers. The addition includes home economics rooms, shops, a real art room and a second gym. Boys get the new one; girls must occupy the old one.
Students occupy themselves with the 10-cent basketball games, weekly assemblies, magazine fund-raisers, and spot, tag, conga and "Paul Jones" dances. What seem to matter most, however, are the changes in the cafeteria. Lunch period is extended to 50 minutes and traditional taboo forbidding boys and girls to eat at the same table is finally lifted.

The most drastic change comes on October 18, 1956 when fire engulfs the halls of the school. awakened by a barking dog, Mrs. Kay Lucas, a nearby resident, notices the flames at 4:15 a.m. Her son, Bert, turns in the alarm. Although the hands of the school clock are stopped at 3:09 a.m., firefighters set the start of the blaze at least one hour earlier. Damage is incredible, as fire quickly destroys the auditorium, the main office, the guidance rooms and the science labs. More than 100 firemen from Port Credit, Cooksville, Lakeview and New Toronto struggle for 8 hours to bring the flames under control.
When it's all over , eleven classrooms are ruined, including all the commercial rooms. The
old wing is completely gutted and the new wing suffers smoke and water damage. All current
records are lost, along with textbooks and other personal belongings kept in lockers. The
library, too, is waterlogged and many books have to be thrown away. The cost of damage is
estimated at over $500,000.
But the Port Credit spirit cannot be diminished by the flames! As firefighters are still pouring water on smouldering ruins, scores of students, armed with mops and pails, move in to clean
up the parts of the school untouched by fire.
The following Monday, students return to class with a few changes in their timetables. In
order to house students until portables arrive, the schedule needs to be flexible. Grade 9's attend school on Mondays, Wednesdays and Fridays. Commercial students find space off school property at St. Andrew's Presbyterian Church and Trinity Anglican Church.