( CNN ) -- Dozens of 911 calls released Wednesday by the Carson City , Nevada , Sheriff 's Office capture the horror of a mass shooting at an IHOP restaurant . In one call , a woman sobs as she tries to give the location of the shooter who fatally shot four others before he killed himself in the parking lot . Others seemed to be left almost speechless by the trauma as they give descriptions and accounts . `` Hurry send ambulances , '' one woman pleads . `` There are people dead . '' A total of 11 people were shot Tuesday , Carson City Sheriff Ken Furlong said . They included five uniformed Army National Guard members and six civilians . Three Guard members , a civilian woman and suspect Eduardo Sencion , 32 , were killed . Authorities were investigating the motive Wednesday . Family members told authorities that Sencion had a history of mental problems dating back to age 16 , a law enforcement official said . Sencion was carrying an assault rifle and a pistol when he went into the IHOP Tuesday morning , Furlong said . Ralph Swagler , owner of the nearby Locals Barbecue , told 911 that the shooter , who wore a red shirt and black pants , was carrying automatic weapons . `` Now he is coming back outside with a gun , '' Swagler said . `` He is shooting people in the parking lot ! '' At that point , the businessman yells for his son to get out of the way . A burst of gunfire is then heard outside the IHOP . `` He is shooting at us now , '' said Swagler , who declined to speak Wednesday with CNN about the incident . `` Automatic weapons . He is shooting at everybody . '' A second assault rifle was found in Sencion 's vehicle , according to authorities . Only the assault rifle he carried was fired , the sheriff said . An IHOP customer talked with 911 operators as he looked inside the restaurant 's window after the rampage . `` Oh my God , we 've got ( expletive ) people down . '' Sencion , who had no prior criminal history , continued firing in the restaurant 's parking lot after shooting the IHOP patrons . Four nearby businesses were hit by gunfire , Furlong said . Emergency operators remained poised during the barrage of 911 calls . `` We 've got help on the way , '' they assured eyewitnesses . `` It was crazy , '' said one witness calling from IHOP . `` It was like a nightmare . '' Furlong said he was the second person to arrive on the scene Tuesday morning . He held a woman shot in the head . `` The scene was horrific . It 's something that I 've never experienced before , '' the sheriff said . `` It looked like a bloodbath , wall-to-wall carnage . '' Investigators are trying to determine whether Sencion obtained the AK-47 used in the shooting lawfully . The released calls include conversations between law enforcement personnel , who are told they need to be on the lookout for possible additional shooters . Sencion acted alone , authorities learned . In one call , an officer is asked if more assistance is needed . `` At this point we have the scene under control , '' was the reply . CNN 's Thelma Gutierrez contributed to this report .
911 callers describe chaotic scene inside , outside Carson City IHOP . He was found dead of self - inflicted wound in parking lot . Four people were injured , including two members of Nevada National Guard .