Passage: John Nelson was the officer who conceived the idea to form a specially trained and equipped unit in the LAPD, intended to respond to and manage critical situations involving shootings while minimizing police casualties. Inspector Gates approved this idea, and he formed a small select group of volunteer officers. This first SWAT unit initially consisted of fifteen teams of four men each, making a total staff of sixty. These officers were given special status and benefits, and were required to attend special monthly training sessions. The unit also served as a security unit for police facilities during civil unrest. The LAPD SWAT units were organized as "D Platoon" in the Metro division.Early police powers and tactics used by SWAT teams were aided by legislation passed in 1967-8 with the help of Republican House representative Donald Santarelli. The legislation was promoted within the context of fears over the Civil Rights Movement, race riots, the Black Panther Party, and the emerging War on Drugs.The first significant deployment of the LAPD's SWAT unit was on December 9, 1969, in a four-hour confrontation with members of the Black Panthers in a densely populated area of Los Angeles. The raid was problematic from the start, leading to a shootout in which Daryl Gates phoned the Department of Defense, requesting and receiving permission to use a grenade launcher. The Panthers eventually surrendered, with four Panthers and four officers being injured. All six arrested Panthers were acquitted of the most serious charges brought against them, including conspiracy to murder police officers, because it was ruled that they acted in self-defense.By 1974, there was a general acceptance of SWAT as a resource for the city and county of Los Angeles.

Question: How many were injured after the Panthers surrendered?
four Panthers and four officers