...is he dead?
According to the top comment and the fact that he has videos made afterwards, no.
According to him, he broke his neck and his neighbor pulled him out of the pool before paramedics came.
The film begins with a clip of Zavadil's most notorious stunt in which he attempted to dive into a covered swimming pool from a ladder. The ladder was unstable and his jump resulted in a head-first landing on the concrete deck. Zavadil then fell into the tarp of the pool, and nearly drowned as it sank until a neighbor came by and saved him. Zavadil fractured his neck as a result requiring a six-month recovery.[4][5] The news of the failed stunt received attention from various international television shows.[6]
Had the stunt gone the way he planned it could've been even more dangerousThe cover would envelop him upon landing and could have gotten him stuck