SYOSSET, N.Y. — One was a young tourist from Minnesota on her way to a Dave Matthews concert. The other, a former Broadway dancer headed home after ballet class.

They both fell victim to a common hazard along the Long Island Rail Road — the gap between the train and platform.

The teenager was killed this month after she slipped through a gap between a Long Island Rail Road car and the platform and was struck by a train going the other way. The dancer broke her neck and was left paralyzed after suffering a similar fall two years ago.

The death of 18-year-old Natalie Smead has prompted advocates, politicians and others to call for North America’s largest commuter railroad to take steps to reduce the number of gap-related injuries. The railroad concedes such injuries happen about once a week.

Critics say the railroad, which placed yellow “Watch the Gap” stickers on all train door windows in the early 1990s, has either never fully addressed the problem or is content that the number of injuries is relatively small compared to the hundreds of thousands who travel safely each day.

“My own take on this is they feel it’s probably cheaper for them to defend lawsuits than to actually fix the problem,” said attorney Paul Weitz, who has filed a $50 million lawsuit on behalf of Shelly Rann — the former Broadway dancer. “They’ve made a heartless calculation that it’s flat out cheaper than to fix the problem.”

Ms. Rann, 67, who was a Radio City Rockette at 16 and danced in Broadway musicals, was returning home from a ballet class in October 2004 when she fell through a gap between the train and platform at the Forest Hills station. She is a quadriplegic because of the accident.

Ms. Smead, an 18-year-old from Northfield, Minn., fell onto the tracks as she was getting off a westbound train at Woodside on August 5, headed for a concert at Randall’s Island. She managed to cross under the platform and was trying to climb up the other side when she was struck by an eastbound train.

Railroad officials said it is the only known fatality attributed to someone falling through the gap, but they concede there have been nearly 130 injuries to commuters slipping through gaps since 2004 —an average of more than one a week at its 124 stations that stretch from Manhattan to Montauk.

In response to Ms. Smead’s death, James Dermody, LIRR president, said officials would install a $1.5 million closed-circuit television system that will allow the conductor to view both ends of the platform at one particularly curvy station — Syosset. The platform at Woodside, where Ms. Smead died, is relatively straight and it is still not clear how the young woman fell.

Judy Jacobs, the leader of the Nassau County Legislature, said cameras are no solution and said the remedy is to install so-called “gap plates,” devices that electronically extend temporary plates from the platform to train doors. Such devices are used in several New York City subway stations.