SAN DIEGO (CBS 8) - Investigators are trying to determine what caused another fire at a Christmas tree recycling lot in Mission Bay Friday night.

The fire was reported just before 8:00 p.m. at the lot in the 1100 block of Sea World Drive. 

Firefighters had the fire out in a short time. No one was injured and no structures were burned.

Investigators say this is the second fire at the lot since last Sunday.