Extreme events are observed in the spatiotemporal chaos dynamics of a three-element laterally coupled laser array. With the help of statistical and dynamical analyses, we confirm that spatiotemporal chaos induces extreme pulses that are high enough to be identified as extreme events and cannot be found in synchronization chaos. Interestingly, our results show that extreme events always preferentially appear in the middle laser as the laser separation ratio is decreased (i.e., upon increasing the coupling strength), and then in the two outer lasers. This thus reveals the importance of the middle laser in the transition between synchronization chaos and spatiotemporal chaos states. Additionally, we show the evolution of extreme events in the plane of the pump level and laser separation ratio by calculating the corresponding proportion. Our results build a relation between extreme events and the spatiotemporal dynamics, which makes it easy to understand the formation mechanism of extreme events.