PENNSYLVANIA - Saturday, in the face of one of the worst snowstorms in the region's history, SEPTA did something unprecedented: It took the massive, regional transportation system and turned most of it off.

About 2:20 p.m., the last three commuter trains rolled into their stations, simultaneously displayed on a video board at the agency control center.

The end of suburban rail service came about seven hours after the Norristown High Speed Line stopped and 12 hours after bus service ended. The trolleys shut down, too.

Only the subways remained operating, the Broad Street Line moving north and south, the Market-Frankford Line east and west.

The phased shutdown was a radical departure for SEPTA. Until yesterday, no matter the strength of a storm, or the depth of the snow, SEPTA pushed its buses, trains, and trolleys until they simply stopped.

One result was the agency spent hours digging out vehicles and freeing stranded passengers. Another was that engines and equipment were wrecked.