Insurance in such forms and in such companies as shall be reasonably approved by the grantor to protect the city and the grantee from and against any and all claims, injury or damage to persons or property, both real and personal, caused by the construction, erection, operation and maintenance of any structure, equipment or appliance in connection with the cable system. The amount of such insurance shall be not less than $1,000,000 combined single limit with a $3,000,000 umbrella, naming both the grantee and the grantor, its officers, agents and employees as additional insureds;