According to USGS:
Magnitude: 7.3
Event Time
2014-10-14 03:51:35 UTC
2014-10-13 21:51:35 UTC-06:00 at epicenter
2014-10-13 21:51:35 UTC-06:00 system time
Location
12.576°N 88.046°W depth=40.0km (24.9mi)
Nearby Cities
67km (42mi) WSW of Jiquilillo, Nicaragua
86km (53mi) SSW of La Union, El Salvador

According to DGOA (El Savador official agency) it was 7.4 magnitude
One person has been unofficialy reported dead and there have been minor damages in some locations, especially in eastern El Salvador.
It was the strongest earthquake in El Salvador since the 7.6 earthquake in January 13 2001 that caused 944 deaths and 1.3 million homeless.