On Monday night, a young mother carrying her toddler in a stroller fell down subway stairs in Manhattan and died.

Malaysia Goodson, 22, died doing what countless others are forced to do each day: navigate a subway system notoriously lacking in accessibility.

Ms. Goodson’s death, in a Midtown station that has no elevator, could be a crystallizing moment for advocates who have been pushing the Metropolitan Transportation Authority to make more stations accessible to disabled riders and to those who find stairs an obstacle.

[Read our story about Ms. Goodson’s death and the battle to make the subways more accessible.]

The numbers are daunting.

• Only 24 percent of the 472 subway stations have elevators, and the elevators that exist break down an average of once a week.