I would presume the Indian Railways number of 15,000 is for the entire system, including intercity, commuter, and freight trains. So the equivalent number for the U.S. would be trespasser fatalities for the entire FRA-regulated railroad system: Amtrak, commuter rail, and all freight railroads.
For the stat geeks: To find the trespasser fatality and other rail accident stats for the US, go to the Bureau of Transportation Statistics website and dive down to the
Data Library: Safety page and go from there. There is a LOT of data available, down to each incident. Should be summary stats on the FRA website as well.
For all railroads that fall under the authority of the FRA (from freight to commuter rail), looks like there were 548 trespasser fatalities and 127 Non-trespasser fatalities in 2012, if I am extracting the stats correctly. 118 of the Non-trespasser fatalities are Highway-Rail Crossing Incidents, so my interpretation is these are grade crossing accidents.
Looking at it by railroad, again if I'm reading the data tables correctly, Amtrak was involved in a total of 111 fatalities in 2012. This number has been declining since 2009 (2009: 139, 2008: 132, 2011: 113), so the safety has been improving. Looks like 70 of the 111 fatalities were trespassers with 35 nonfatal trespassers injuries. There were 36 Highway-Rail incident fatalities in 2012, down from 51 in 2009.
For comparison, CSX was involved in 101 fatalities in 2012, 67 of those trespassers. UP was involved in 133 fatalities in 2012, 74 of those trespassers, 5 employee fatalities.
The rail statistics do NOT include transit systems such as the NYC subway, DC Metro, and so on. There is a separate Transit classification I have not examined.
If anyone wants to dig up detailed stats on India and other countries, be my guest. But take care to make sure there is some equivalence in the stats.