Appearing on “60 Minutes” Sunday night, family members of the victims killed in the Newtown, Connecticut massacre said that limiting the sales of high-capacity magazines is “crucial” to any effort that hopes to prevent another similar event.

The families are members of the group Sandy Hook Promise, which launched a petition urging lawmakers to honor the victims by committing to passing gun control legislation.

Bill Sherlach, whose wife lost her life trying to stop the shooter, said that limiting magazine size is particular “critical” because “you can have a million bullets, but if you have to put them in one at a time, the ability to do any kind of real damage is significantly reduced.”

The shooter in Newtown, Adam Lanza, walked into the Sandy Hook elementary school armed with a semi-automatic Bushmaster AR-15 and 10 extended magazines with 30 bullets each, firing a total of 155 bullets in just less than 5 minutes — a rate of roughly two bullets per second. A shocking toll resulted: 26 people dead, including 20 children.