Seven of Ontario's 10,500 full-time firefighters have ALS, much higher than in the general population .
The problems started for Al Pettit five years ago with a nagging weakness, and a peculiar feeling beneath his skin.
“One day I was sitting on the toilet. I looked down, and I noticed my calf was wiggling,” said the former Mississauga firefighter. At the time, he was on a seven-week trip to the Philippines. He attributed the twitching to his tiring travels, and to overindulging in foreign beer.