Regardless of the failure... always start with the basics, if for no other reason, for peace of mind and to get them out of the way...... Compression, what are the psi readings?... Spark test, spark should jump a 7/16" gap with a strong blue lightning like flame... does it?
More info is needed.... does the engine stop suddenly like one turned the key OFF.... or gradually slow down and stop? Are you able to crank the engine over immediately after it stops or is it seized for a few minutes, then loosens up?