Mongod - Service keeps receiving signal 15

After repair my database, every time the service for mongod start, it tries to rebuild the indexes, but at the start it keeping receiving signal 15 and it restarts the service. Why this is happening? Here is the log:

2018-11-19T15:59:05.668+0000 I INDEX    [initandlisten]      building index using bulk method; build may temporarily use up to 250 megabytes of RAM
2018-11-19T15:59:08.010+0000 I -        [initandlisten]   Index Build: 34500/12528425 0%
2018-11-19T15:59:11.043+0000 I -        [initandlisten]   Index Build: 39500/12528425 0%
2018-11-19T15:59:14.010+0000 I -        [initandlisten]   Index Build: 46400/12528425 0%
2018-11-19T15:59:17.043+0000 I -        [initandlisten]   Index Build: 64100/12528425 0%
2018-11-19T15:59:20.035+0000 I -        [initandlisten]   Index Build: 82200/12528425 0%
2018-11-19T15:59:23.052+0000 I -        [initandlisten]   Index Build: 87200/12528425 0%
2018-11-19T15:59:26.027+0000 I -        [initandlisten]   Index Build: 112600/12528425 0%
2018-11-19T15:59:29.010+0000 I -        [initandlisten]   Index Build: 117400/12528425 0%
2018-11-19T15:59:32.010+0000 I -        [initandlisten]   Index Build: 123700/12528425 0%
2018-11-19T15:59:35.010+0000 I -        [initandlisten]   Index Build: 129100/12528425 1%
2018-11-19T15:59:38.077+0000 I -        [initandlisten]   Index Build: 134700/12528425 1%
2018-11-19T15:59:41.035+0000 I -        [initandlisten]   Index Build: 182800/12528425 1%
2018-11-19T15:59:44.069+0000 I -        [initandlisten]   Index Build: 237900/12528425 1%
2018-11-19T15:59:47.037+0000 I -        [initandlisten]   Index Build: 278000/12528425 2%
2018-11-19T15:59:50.019+0000 I -        [initandlisten]   Index Build: 317500/12528425 2%
2018-11-19T15:59:53.019+0000 I -        [initandlisten]   Index Build: 516500/12528425 4%
2018-11-19T15:59:56.002+0000 I -        [initandlisten]   Index Build: 540200/12528425 4%
2018-11-19T15:59:59.061+0000 I -        [initandlisten]   Index Build: 545200/12528425 4%
2018-11-19T16:00:02.011+0000 I -        [initandlisten]   Index Build: 575000/12528425 4%
2018-11-19T16:00:03.572+0000 I CONTROL  [signalProcessingThread] got signal 15 (Terminated), will terminate after current cmd ends

The version of Mongo is 3.2 and it is running on EC2 instance.